Journal articles: 'Antiferromagnet'

1

CHANG, ZHE. "GREEN'S FUNCTION THEORY OF THE DOPED ANISOTROPIC ANTIFERROMAGNET." International Journal of Modern Physics B 14, no. 10 (April 20, 2000): 1037–57. http://dx.doi.org/10.1142/s0217979200001497.

Full text

Abstract:

The Green's function theory of the t–J model is generalized to investigate phase diagram and magnetic properties of the doped anisotropic antiferromagnet, which is believed to describe the elementary properties of the high-temperature superconductors. Antiferromagnetic–metalic phase transition is shown. The explicit dependence of the Néel temperature and sublattice magnetization of the anisotropic doped antiferromagnets on anisotropic parameter ς, doping density δ and parameters of the t–J model are obtained for small doping concentration.

APA, Harvard, Vancouver, ISO, and other styles

2

Tsoi, Maxim. "Antiferromagnetic spintronics: From metals to functional oxides." Low Temperature Physics 49, no. 7 (July 1, 2023): 786–93. http://dx.doi.org/10.1063/10.0019689.

Full text

Abstract:

Antiferromagnetic spintronics exploits unique properties of antiferromagnetic materials to create new and improved functionalities in future spintronic applications. Here, we briefly review the experimental efforts in our group to unravel spin transport properties in antiferromagnetic materials. Our investigations were initially focused on metallic antiferromagnets, where the first evidence of antiferromagnetic spin-transfer torque was discovered. Because of the lack of metallic antiferromagnets, we then shifted towards antiferromagnetic Mott insulators, where a plethora of transport phenomena was found. For instance, we observed a very large anisotropic magnetoresistance, which can be used to detect the magnetic state of an antiferromagnet. We also observed reversible resistive switching and now provide unequivocal evidence that the resistive switching is associated with structural distortions driven by an electric field. Our findings support the potential of electrically controlled functional oxides for various memory technologies.

APA, Harvard, Vancouver, ISO, and other styles

3

Coileáin, Cormac Ó., and Han Chun Wu. "Materials, Devices and Spin Transfer Torque in Antiferromagnetic Spintronics: A Concise Review." SPIN 07, no. 03 (September 2017): 1740014. http://dx.doi.org/10.1142/s2010324717400148.

Full text

Abstract:

From historical obscurity, antiferromagnets are recently enjoying revived interest, as antiferromagnetic (AFM) materials may allow the continued reduction in size of spintronic devices. They have the benefit of being insensitive to parasitic external magnetic fields, while displaying high read/write speeds, and thus poised to become an integral part of the next generation of logical devices and memory. They are currently employed to preserve the magnetoresistive qualities of some ferromagnetic based giant or tunnel magnetoresistance systems. However, the question remains how the magnetic states of an antiferromagnet can be efficiently manipulated and detected. Here, we reflect on AFM materials for their use in spintronics, in particular, newly recognized antiferromagnet Mn2Au with its in-plane anisotropy and tetragonal structure and high Néel temperature. These attributes make it one of the most promising candidates for AFM spintronics thus far with the possibility of architectures freed from the need for ferromagnetic (FM) elements. Here, we discuss its potential for use in ferromagnet-free spintronic devices.

APA, Harvard, Vancouver, ISO, and other styles

4

WENG, ZHENG-YU. "PHASE STRING THEORY FOR DOPED ANTIFERROMAGNETS." International Journal of Modern Physics B 21, no. 06 (March 10, 2007): 773–827. http://dx.doi.org/10.1142/s0217979207036722.

Full text

Abstract:

The recent developments of the phase string theory for doped antiferromagnets will be briefly reviewed. Such theory is built upon a singular phase string effect induced by the motion of holes in a doped antiferromagnet, which as a precise property of the t-J model dictates the novel competition between the charge and spin degrees of freedom. A global phase diagram including the antiferromagnetic, superconducting, lower and upper pseudogap, and high-temperature "normal" phases, as well as a series of anomalous physical properties of these phases will be presented as the self-consistent and systematic consequences of the phase string theory.

APA, Harvard, Vancouver, ISO, and other styles

5

Lima, Leonardo S. "Entanglement Negativity and Concurrence in Some Low-Dimensional Spin Systems." Entropy 24, no. 11 (November 10, 2022): 1629. http://dx.doi.org/10.3390/e24111629.

Full text

Abstract:

The influence of magnon bands on entanglement in the antiferromagnetic XXZ model on a triangular lattice, which models the bilayer structure consisting of an antiferromagnetic insulator and normal metal, is investigated. This effect was studied in ferromagnetic as well as antiferromagnetic triangular lattices. Quantum entanglement measures given by the entanglement negativity have been studied, where a magnon current is induced in the antiferromagnet due to interfacial exchange coupling between localized spins in the antiferromagnet and itinerant electrons in a normal metal. Moreover, quantum correlations in other frustrated models, namely the metal-insulation antiferromagnetic bilayer model and the Heisenberg model with biquadratic and bicubic interactions, are analyzed.

APA, Harvard, Vancouver, ISO, and other styles

6

Maniv, Eran, Nityan L. Nair, Shannon C. Haley, Spencer Doyle, Caolan John, Stefano Cabrini, Ariel Maniv, et al. "Antiferromagnetic switching driven by the collective dynamics of a coexisting spin glass." Science Advances 7, no. 2 (January 2021): eabd8452. http://dx.doi.org/10.1126/sciadv.abd8452.

Full text

Abstract:

The theory behind the electrical switching of antiferromagnets is premised on the existence of a well-defined broken symmetry state that can be rotated to encode information. A spin glass is, in many ways, the antithesis of this state, characterized by an ergodic landscape of nearly degenerate magnetic configurations, choosing to freeze into a distribution of these in a manner that is seemingly bereft of information. Here, we show that the coexistence of spin glass and antiferromagnetic order allows a novel mechanism to facilitate the switching of the antiferromagnet Fe1/3 + δNbS2, rooted in the electrically stimulated collective winding of the spin glass. The local texture of the spin glass opens an anisotropic channel of interaction that can be used to rotate the equilibrium orientation of the antiferromagnetic state. Manipulating antiferromagnetic spin textures using a spin glass’ collective dynamics opens the field of antiferromagnetic spintronics to new material platforms with complex magnetic textures.

APA, Harvard, Vancouver, ISO, and other styles

7

Kalita, V. M., G. Yu Lavanov, and V. M. Loktev. "Magnetization and Magnetocaloric Effect in Antiferromagnets with Competing Ising Exchange and Single-Ion Anisotropies." Ukrainian Journal of Physics 65, no. 10 (October 9, 2020): 858. http://dx.doi.org/10.15407/ujpe65.10.858.

Full text

Abstract:

The magnetization of a two-sublattice Ising antiferromagnet with easy-plane single-ion anisotropy, which is accompanied by two phase transitions, has been studied. The both phase transitions are induced by the magnetic field. One of them is isostructural, i.e., the system symmetry remains unchanged and a transition between two antiferromagnetic states with different sublattice magnetizations takes place. The other phase transition occurs when the antiferromagnetic state transforms into the ferromagnetic one. At both phase transitions, the field dependence of the system entropy has two successive positive jumps, which is not typical of ordinary antiferromagnets. On the other hand, if the temperature of the system is higher than the tricritical temperature of the isostructural phase transition, there appears a continuous maximum in the field dependence of the entropy.

APA, Harvard, Vancouver, ISO, and other styles

8

Deng, Panluo, Fengjun Zhuo, Hang Li, and Zhenxiang Cheng. "Mirroring Skyrmions in Synthetic Antiferromagnets via Modular Design." Nanomaterials 13, no. 5 (February 25, 2023): 859. http://dx.doi.org/10.3390/nano13050859.

Full text

Abstract:

Skyrmions are promising for the next generation of spintronic devices, which involves the production and transfer of skyrmions. The creation of skyrmions can be realized by a magnetic field, electric field, or electric current while the controllable transfer of skyrmions is hindered by the skyrmion Hall effect. Here, we propose utilizing the interlayer exchange coupling induced by the Ruderman–Kittel–Kasuya–Yoshida interactions to create skyrmions through hybrid ferromagnet/synthetic antiferromagnet structures. An initial skyrmion in ferromagnetic regions could create a mirroring skyrmion with an opposite topological charge in antiferromagnetic regions driven by the current. Furthermore, the created skyrmions could be transferred in synthetic antiferromagnets without deviations away from the main trajectories due to the suppression of the skyrmion Hall effect in comparison to the transfer of the skyrmion in ferromagnets. The interlayer exchange coupling can be tuned, and the mirrored skyrmions can be separated when they reach the desired locations. Using this approach, the antiferromagnetic coupled skyrmions can be repeatedly created in hybrid ferromagnet/synthetic antiferromagnet structures. Our work not only supplies a highly efficient approach to create isolated skyrmions and correct the errors in the process of skyrmion transport, but also paves the way to a vital information writing technique based on the motion of skyrmions for skyrmion-based data storage and logic devices.

APA, Harvard, Vancouver, ISO, and other styles

9

Borynskyi, V. Yu, D. M. Polishchuk, Yu O. Savina, V. O. Pashchenko, A. F. Kravets, A. I. Tovstolytkin, and V. Korenivski. "Thermomagnetic transition in nanoscale synthetic antiferromagnets Py/NiCu/Py." Low Temperature Physics 49, no. 7 (July 1, 2023): 863–69. http://dx.doi.org/10.1063/10.0019699.

Full text

Abstract:

Using the method of SQUID magnetometry, the features of the antiferromagnet-ferromagnet thermomagnetic transition in arrays of the nanosized disks of Py/NiCu/Py synthetic antiferromagnets (SAFs) have been investigated. The effective interlayer interaction in individual SAFs “ferromagnet/diluted ferromagnet/ferromagnet” (F2/f/F1) changes from high-temperature antiferromagnetic to low-temperature ferromagnetic upon the transition at the Curie temperature TCf of the interlayer f. Temperature dependence of the magnetic parameters of individual layers and their effect on the features of the thermomagnetic transition are determined. The observed properties are important for the development of temperature-controlled nanoscale SAFs and multilayer nanostructures based on them.

APA, Harvard, Vancouver, ISO, and other styles

10

Sato, Yuma, Yutaro Takeuchi, Yuta Yamane, Ju-Young Yoon, Shun Kanai, Jun’ichi Ieda, Hideo Ohno, and Shunsuke Fukami. "Thermal stability of non-collinear antiferromagnetic Mn₃Sn nanodot." Applied Physics Letters 122, no. 12 (March 20, 2023): 122404. http://dx.doi.org/10.1063/5.0135709.

Full text

Abstract:

D019-Mn3Sn, an antiferromagnet having a non-collinear spin structure in a kagome lattice, has attracted great attention owing to various intriguing properties such as large anomalous Hall effect. Stability of a magnetic state against thermal fluctuation, characterized in general by the thermal stability factor Δ, has been well studied in ferromagnetic systems but not for antiferromagnets. Here, we study Δ of the antiferromagnetic Mn3Sn nanodots as a function of their diameter D. To quantify Δ, we measure the switching probability as a function of the pulse-field amplitude and analyze the results based on a model taking account of two and sixfold magnetic anisotropies in the kagome plane. We observe no significant change in Δ down to D = 300 nm below which it decreases with D. The obtained D dependence is well explained by a single-domain and nucleation-mediated reversal models. These findings provide a basis to understand the thermal fluctuation and reversal mechanism of antiferromagnets for device applications.

APA, Harvard, Vancouver, ISO, and other styles

11

Ślęzak, M., P. Dróżdż, W. Janus, H. Nayyef, A. Kozioł-Rachwał, M. Szpytma, M. Zając, et al. "Correction: Fine tuning of ferromagnet/antiferromagnet interface magnetic anisotropy for field-free switching of antiferromagnetic spins." Nanoscale 12, no. 37 (2020): 19477. http://dx.doi.org/10.1039/d0nr90207a.

Full text

Abstract:

Correction for ‘Fine tuning of ferromagnet/antiferromagnet interface magnetic anisotropy for field-free switching of antiferromagnetic spins’ by M. Ślęzak et al., Nanoscale, 2020, DOI: 10.1039/d0nr04193a.

APA, Harvard, Vancouver, ISO, and other styles

12

Kosaka, Wataru, Masahisa Itoh, and Hitoshi Miyasaka. "Metamagnetism with TN = 97 K in a layered assembly of paddlewheel [Ru2] units and TCNQ: an empirical rule for interlayer distances determining the magnetic ground state." Materials Chemistry Frontiers 2, no. 3 (2018): 497–504. http://dx.doi.org/10.1039/c7qm00534b.

Full text

Abstract:

A new layered antiferromagnet was synthesized from the reaction of a paddlewheel diruthenium(ii,ii) complex with a TCNQ derivative. The complex has a short interlayer distance and forms part of a series of layered antiferromagnets.

APA, Harvard, Vancouver, ISO, and other styles

13

Soh, Yeong-Ah, and Ravi K. Kummamuru. "Spintronics in antiferromagnets." Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 369, no. 1951 (September 28, 2011): 3646–57. http://dx.doi.org/10.1098/rsta.2011.0186.

Full text

Abstract:

Magnetic domains and the walls between are the subject of great interest because of the role they play in determining the electrical properties of ferromagnetic materials and as a means of manipulating electron spin in spintronic devices. However, much less attention has been paid to these effects in antiferromagnets, primarily because there is less awareness of their existence in antiferromagnets, and in addition they are hard to probe since they exhibit no net magnetic moment. In this paper, we discuss the electrical properties of chromium, which is the only elemental antiferromagnet and how they depend on the subtle arrangement of the antiferromagnetically ordered spins. X-ray measurement of the modulation wavevector Q of the incommensurate antiferromagnetic spin-density wave shows thermal hysteresis, with the corresponding wavelength being larger during cooling than during warming. The thermal hysteresis in the Q vector is accompanied with a thermal hysteresis in both the longitudinal and Hall resistivity. During cooling, we measure a larger longitudinal and Hall resistivity compared with when warming, which indicates that a larger wavelength at a given temperature corresponds to a smaller carrier density or equivalently a larger antiferromagnetic ordering parameter compared to a smaller wavelength. This shows that the arrangement of the antiferromagnetic spins directly influences the transport properties. In thin films, the sign of the thermal hysteresis for Q is the same as in thick films, but a distinct aspect is that Q is quantized.

APA, Harvard, Vancouver, ISO, and other styles

14

CAPRIOTTI, LUCA. "QUANTUM EFFECTS AND BROKEN SYMMETRIES IN FRUSTRATED ANTIFERROMAGNETS." International Journal of Modern Physics B 15, no. 12 (May 20, 2001): 1799–842. http://dx.doi.org/10.1142/s0217979201004605.

Full text

Abstract:

We investigate the interplay between frustration and zero-point quantum fluctuations in the ground state of the triangular and J1–J2 Heisenberg antiferromagnets, using finite-size spin-wave theory, exact diagonalization, and quantum Monte Carlo methods. In the triangular Heisenberg antiferromagnet, by performing a systematic size-scaling analysis, we have obtained strong evidences for a gapless spectrum and a finite value of the thermodynamic order parameter, thus confirming the existence of long-range Néel order. The good agreement between the finite-size spin-wave results and the exact and quantum Monte Carlo data also supports the reliability of the spin-wave expansion to describe both the ground state and the low-energy spin excitations of the triangular Heisenberg antiferromagnet. In the J1–J2 Heisenberg model, our results indicate the opening of a finite gap in the thermodynamic excitation spectrum at J2/J1≃0.4, marking the melting of the antiferromagnetic Néel order and the onset of a non-magnetic ground state. In order to characterize the nature of the latter quantum-disordered phase we have computed the susceptibilities for the most important crystal symmetry breaking operators. In the ordered phase the effectiveness of the spin-wave theory in reproducing the low-energy excitation spectrum suggests that the uniform spin susceptibility of the model is very close to the linear spin-wave prediction.

APA, Harvard, Vancouver, ISO, and other styles

15

Liu, Ping, Hanpeng Zhu, Qingmei Wu, Yalin Lu, and Yong Pu. "Unconventional magneto-transport properties of the layered antiferromagnet Fe_1/3NbS₂." Applied Physics Letters 121, no. 8 (August 22, 2022): 081901. http://dx.doi.org/10.1063/5.0098797.

Full text

Abstract:

Recently, magnetically intercalated layered transition metal dichalcogenide Fe1/3NbS2 has attracted considerable attention due to its promise for spintronics applications, especially for the demonstration of reversible resistance switching by electrical stimulation below the antiferromagnetic transition temperature. Magneto-transport properties and their correlation to the underlying magnetic configurations are yet to be clarified in Fe1/3NbS2. Herein, we investigate the magneto-transport behavior of antiferromagnet Fe1/3NbS2, demonstrating a complex behavior of the magnetoresistance and unconventional Hall effect. The resistance of this compound displayed metallic behavior and an abrupt decrease at TN. Of particular interest, the positive magnetoresistance is enhanced and it reaches a maximum in the vicinity of Néel temperature as a function of the out-of-plane magnetic field, which is in contrast to most of the antiferromagnets. Meanwhile, the Hall signal showed an unusual nonlinear field-dependence in the same temperature range. Moreover, the magnetoresistance exhibits a significant anisotropy, up to 14% near the Néel temperature. We attributed these unconventional magneto-transport behaviors to the field induced formation of a complex spin texture in Fe1/3NbS2. Our work motivates further efforts on antiferromagnetic spintronic devices based on this intercalated layered transition metal dichalcogenide.

APA, Harvard, Vancouver, ISO, and other styles

16

Сафин, А. Р., Е. Е. Козлова, Д. В. Калябин, and С. А. Никитов. "Детектирование терагерцевых электромагнитных волн с помощью проводящих антиферромагнетиков." Письма в журнал технической физики 47, no. 16 (2021): 20. http://dx.doi.org/10.21883/pjtf.2021.16.51323.18840.

Full text

Abstract:

We investigate a mathematical model of a terahertz electromagnetic wave detector based on a conducting antiferromagnet and a heavy metal. The mechanism of resonant straightening of oscillations is based on the inverse spin Hall effect in a heavy metal under spin pumping from an antiferromagnet. It is shown that the frequency dependence of the constant voltage of the detector has a resonant character with a peak corresponding to the frequency of antiferromagnetic resonance. The sensitivity to an alternating terahertz signal of the proposed detector structure is comparable to the sensitivity of modern detectors based on Schottky and Gunn diodes.

APA, Harvard, Vancouver, ISO, and other styles

17

Wang, Jiao-Yang, Qian Yang, Yi-Quan Zhang, Guang-Bo Che, Jiong-Peng Zhao, and Fu-Chen Liu. "Two isomorphous azide/formate Mn(ii) coordination polymers show spin-canted antiferromagnetism only in the formate system." Inorganic Chemistry Frontiers 5, no. 3 (2018): 719–22. http://dx.doi.org/10.1039/c7qi00789b.

Full text

Abstract:

We reported two isomorphous azide/formate Mn^II complexes: the azide complex had normal antiferromagnetic coupling, while a canted antiferromagnet with a Néel temperature of T_N = 38.5 K was obtained in the formate system.

APA, Harvard, Vancouver, ISO, and other styles

18

Migachev, S. A., M. F. Sadykov, M. M. Shakirzyanov, and D. A. Ivanov. "Antiferromagnetic Conic Refraction of Sound in Hematite." Solid State Phenomena 168-169 (December 2010): 173–76. http://dx.doi.org/10.4028/www.scientific.net/ssp.168-169.173.

Full text

Abstract:

In a trigonal easy-plane -Fe2O3 antiferromagnet magnetic-field-dependent conic refraction due to the renormalization of the coefficients of elasticity effective magnetoelastic interaction is experimentally found in addition to the conventional internal conic refraction of the transverse elastic waves propagating along the trigonal C3 axis. It is shown that the deflection angle () of the energy flow from the C3 axis upon the internal conic refraction does not depend on the value of the magnetic field applied in the basis plane (HC3) and is a constant value determined by the correlation of the C14 and C44 coefficients of elasticity. The deflection angle of the energy flow upon the antiferromagnetic conic refraction () increases with increase in the field and tends to the  value at large H values. The obtained results agree well with the theory of this phenomenon in antiferromagnets and support its conclusions.

APA, Harvard, Vancouver, ISO, and other styles

19

Vaidya, Priyanka, Sophie A. Morley, Johan van Tol, Yan Liu, Ran Cheng, Arne Brataas, David Lederman, and Enrique del Barco. "Subterahertz spin pumping from an insulating antiferromagnet." Science 368, no. 6487 (April 9, 2020): 160–65. http://dx.doi.org/10.1126/science.aaz4247.

Full text

Abstract:

Spin-transfer torque and spin Hall effects combined with their reciprocal phenomena, spin pumping and inverse spin Hall effects (ISHEs), enable the reading and control of magnetic moments in spintronics. The direct observation of these effects remains elusive in antiferromagnetic-based devices. We report subterahertz spin pumping at the interface of the uniaxial insulating antiferromagnet manganese difluoride and platinum. The measured ISHE voltage arising from spin-charge conversion in the platinum layer depends on the chirality of the dynamical modes of the antiferromagnet, which is selectively excited and modulated by the handedness of the circularly polarized subterahertz irradiation. Our results open the door to the controlled generation of coherent, pure spin currents at terahertz frequencies.

APA, Harvard, Vancouver, ISO, and other styles

20

IOFFE, L. B., and A. I. LARKIN. "EFFECTIVE ACTION OF A TWO-DIMENSIONAL ANTIFERROMAGNET." International Journal of Modern Physics B 02, no. 02 (April 1988): 203–19. http://dx.doi.org/10.1142/s0217979288000160.

Full text

Abstract:

In the limit of weak quantum fluctuations an effective long-wave action of the Heisenberg quantum antiferromagnet is obtained which allows one to get a spectrum, spin, and statistics of long-wave fluctuations. In the vicinity of the point of instability of an antiferromagnetic state quantum fluctuations result (at zero temperature as well) in a paramagnetic phase of a spin liquid.

APA, Harvard, Vancouver, ISO, and other styles

21

SEMENOFF, GORDON W. "STRONG COUPLING QED BREAKS CHIRAL SYMMETRY." Modern Physics Letters A 07, no. 30 (September 28, 1992): 2811–18. http://dx.doi.org/10.1142/s0217732392004183.

Full text

Abstract:

We show that the strong coupling limit of d-dimensional quantum electrodynamics with 2d/2[d/2] flavors of fermions can be mapped onto the s=1/2 quantum Heisenberg antiferromagnet in d–1 space dimensions. We use this mapping to prove that the strong coupling limit of QED breaks chiral symmetry. The staggered Néel order parameter of the antiferromagnet is the expectation value of a mass operator in QED and the spin-waves are pions. We speculate that the chiral symmetry breaking phase transition corresponds to a transition between the flux phase and the conventional Néel ordered phase of an antiferromagnetic t-J model.

APA, Harvard, Vancouver, ISO, and other styles

22

Козлова, Е. Е., and А. Р. Сафин. "Детектирование субтерагерцевых колебаний на основе гетероструктуры антиферромагнетик/тяжелый металл." Письма в журнал технической физики 48, no. 9 (2022): 44. http://dx.doi.org/10.21883/pjtf.2022.09.52451.19079.

Full text

Abstract:

We study a model of a detector of subterahertz electromagnetic waves based on an array of heterostructures containing an antiferromagnet and a heavy metal. We show that the operating frequency of the detector can be tuned by a constant magnetic field applied in the direction of the easy magnetization axis of the antiferromagnet. The dependence of the rectified voltage on the frequency of the external electromagnetic wave for different values of the constant magnetic field is resonant in nature, and an increase in the constant magnetic field leads to an increase in the resonance peak. It is shown that the use of an array of antiferromagnets in the form of a comb structure makes it possible to increase the level of the rectified output voltage.

APA, Harvard, Vancouver, ISO, and other styles

23

Mukhin, A. A., M. Biberacher, A. Pimenov, and A. Loidl. "Antiferromagnetic resonances and magnetization of a canted antiferromagnet." Journal of Magnetic Resonance 170, no. 1 (September 2004): 8–14. http://dx.doi.org/10.1016/j.jmr.2004.05.019.

Full text

APA, Harvard, Vancouver, ISO, and other styles

24

Clark, Judith, Chongin Pak, Huibo Cao, and Michael Shatruk. "Helimagnetism in MnBi2Se4 Driven by Spin-Frustrating Interactions Between Antiferromagnetic Chains." Crystals 11, no. 3 (February 27, 2021): 242. http://dx.doi.org/10.3390/cryst11030242.

Full text

Abstract:

We report the magnetic properties and magnetic structure determination for a linear-chain antiferromagnet, MnBi2Se4. The crystal structure of this material contains chains of edge-sharing MnSe6 octahedra separated by Bi atoms. The magnetic behavior is dominated by intrachain antiferromagnetic (AFM) interactions, as demonstrated by the negative Weiss constant of −74 K obtained by the Curie–Weiss fit of the paramagnetic susceptibility measured along the easy-axis magnetization direction. The relative shift of adjacent chains by one-half of the chain period causes spin frustration due to interchain AFM coupling, which leads to AFM ordering at TN = 15 K. Neutron diffraction studies reveal that the AFM ordered state exhibits an incommensurate helimagnetic structure with the propagation vector k = (0, 0.356, 0). The Mn moments are arranged perpendicular to the chain propagation direction (the crystallographic b axis), and the turn angle around the helix is 128°. The magnetic properties of MnBi2Se4 are discussed in comparison to other linear-chain antiferromagnets based on ternary mixed-metal halides and chalcogenides.

APA, Harvard, Vancouver, ISO, and other styles

25

Barker, Christopher E. A., Eloi Haltz, Thomas A. Moore, and Christopher H. Marrows. "Breathing modes of skyrmion strings in a synthetic antiferromagnet multilayer." Journal of Applied Physics 133, no. 11 (March 21, 2023): 113901. http://dx.doi.org/10.1063/5.0142772.

Full text

Abstract:

Skyrmions are small topologically protected magnetic structures that hold promise for applications from data storage to neuromorphic computing and they have been shown to possess internal microwave frequency excitations. Skyrmions in a synthetic antiferromagnet have been predicted to be smaller and faster than their ferromagnetic equivalents and also shown to possess more internal modes. In this work, we consider the breathing modes of skyrmions in a four repetition synthetic antiferromagnetic multilayer by means of micromagnetic simulations and examine the further splitting of the modes into different arrangements of out-of-phase, in-phase, and modes with more complex phase relationships. This results in a lowering of frequencies, which is promising for skyrmion sensing applications in a synthetic antiferromagnet.

APA, Harvard, Vancouver, ISO, and other styles

26

RICHTER, J., R. DARRADI, R. ZINKE, and R. F. BISHOP. "FRUSTRATED QUANTUM ANTIFERROMAGNETS: APPLICATION OF HIGH-ORDER COUPLED CLUSTER METHOD." International Journal of Modern Physics B 21, no. 13n14 (May 30, 2007): 2273–88. http://dx.doi.org/10.1142/s0217979207043658.

Full text

Abstract:

We report on recent results for strongly frustrated quantum J1 - J2 antiferromagnets in dimensionality d = 1, 2, 3 obtained by the coupled cluster method (CCM). We demonstrate that the CCM in high orders of approximation allows us to investigate quantum phase transitions driven by frustration and to discuss novel quantum ground states. In detail we consider the ground-state properties of (i) the Heisenberg spin-1/2 antiferromagnet on the cubic lattice in d = 1, 2, 3, and use the results for the energy, the sublattice magnetization and the spin stiffness as a benchmark test for the precision of the method; (ii) coupled frustrated spin chains (the quasi-one-dimensional J1 - J2 model) and discuss the influence of the quantum fluctuations and the interchain coupling on the incommensurate spiral state present in the classical model; (iii) the Shastry-Sutherland antiferromagnet on the square lattice; and (iv) a stacked frustrated square-lattice Heisenberg antiferromagnet (the quasi-two-dimensional J1 - J2 model), and discuss the influence of the interlayer coupling on the quantum paramagnetic ground-state phase that is present for the strictly two-dimensional model.

APA, Harvard, Vancouver, ISO, and other styles

27

Джунь, И. О., Г. В. Бабайцев, М. Г. Козин, И. Л. Ромашкина, Е. И. Шанова, and Н. Г. Чеченин. "Влияние внешних факторов на ширину линии ферромагнитного резонанса в структурах с обменным смещением." Физика твердого тела 63, no. 6 (2021): 693. http://dx.doi.org/10.21883/ftt.2021.06.50924.185.

Full text

Abstract:

Extrinsic factors contributing to the ferromagnetic resonance (FMR) line width in double layer (ferromagnet/antiferromagnet) systems with exchange bias were investigated. Dependence of the FMR line width on the thickness of the antiferromagnetic (AF) layer at a constant thickness of the ferromagnetic (F) layer and layers deposition order of the F - and AF - layers, as well as the correlation between the exchange bias and the surface roughness of the sample were studied. We found that the exchange bias has a minor, if any, contribution to the line width. In systems with an antiferromagnet deposited on a ferromagnetic layer, the width of the FMR line increases in proportion to the average size of the surface roughness. In systems with reversal layer sequence the uniaxial anisotropy provides a significant contribution to the line width. The width of the FMR line is in a quadratic dependence on the uniaxial anisotropy and inversely proportional to the thickness of the antiferromagnetic layer, which can be attributed to the effect of the microstructure evolution with the thickness as an extrinsic factor in the damping of the FMR.

APA, Harvard, Vancouver, ISO, and other styles

28

A.F. Kabychenkov and F.V. Lisovsky. "Light-induced flexoantiferomagnetic effect in centroantisymmetric antiferromagnets." Technical Physics 92, no. 3 (2022): 369. http://dx.doi.org/10.21883/tp.2022.03.53267.276-21.

Full text

Abstract:

It is shown that an inhomogeneous circularly polarized light wave induces components of the antiferromagnetism vector in centroantisymmetric antiferromagnets; a narrow beam of light can create a skyrmion. The analysis of the possibility of practical use of the predicted effects is carried out. Keywords: optomagnetic effect, polyharmonic light field, light-induced magnetic field, centroantisymmetric antiferromagnet, circularly polarized light wave, flexoantiferromagnetic effect.

APA, Harvard, Vancouver, ISO, and other styles

29

Weng, Yakui, Fei Long, and Xing'ao Li. "Magnetic order and electronic structure of [110]-oriented LaTiO₃ films: A theoretical study." Europhysics Letters 136, no. 2 (October 1, 2021): 27005. http://dx.doi.org/10.1209/0295-5075/ac35f5.

Full text

Abstract:

Abstract The epitaxial strain effects on the magnetic ground state and electronic structure of [110]-oriented LaTiO3 films have been calculated using the density functional theory. First, the lattice constants of the a-axis and c-axis are fixed to study. For the compressive strain, a magnetic phase transition from the original G-type antiferromagnet to A-type antiferromagnet is predicted when using the SrTiO3, LaGaO3, and LaAlO3 substrates, similar to the [001] case. Interestingly, a new magnetic phase, i.e., the ferromagnetic order, will appear when the larger compressive LaSrAlO4 is used. For the tensile strain, although the G-type antiferromagnetic order is robust as the ground state, the exchange couplings are significantly increased, which will enhance the Néel temperature. Furthermore, the contributions of d yz , d xz and d xy orbitals to the bands near the Fermi level show an obvious difference due to the Jahn-Teller distortions. For comparison, the case with fixed b-axis and c-axis is also tested, which shows that the compressive strained LaTiO3 remains the G-type antiferromagnetic order while the tensile strained LaTiO3 exhibits the A-type antiferromagnetic order. The underlying physical mechanisms are the lattice distortions, including the Ti-O-Ti bond angles and Ti-O bond lengths.

APA, Harvard, Vancouver, ISO, and other styles

30

Wang, Xiaoning, Hongyu Chen, Han Yan, Peixin Qin, Xiaorong Zhou, Ziang Meng, Li Liu, Xiaofang Liu, Hui Wang, and Zhiqi Liu. "Room-temperature magnetoresistance in a single-layer composite film based on noncollinear antiferromagnetic Mn₃Sn." Applied Physics Letters 122, no. 15 (April 10, 2023): 152403. http://dx.doi.org/10.1063/5.0146212.

Full text

Abstract:

The recently discovered room-temperature magnetoresistance in all-antiferromagnetic tunnel junctions is promising for highly integrated ultrafast memory applications. Here, we report a room-temperature magnetoresistance effect in a single-layer composite film consisting of noncollinear antiferromagnetic Mn3Sn and nonmagnetic Ag. A room-temperature butterfly like magnetoresistance of ∼0.3% is obtained for the Mn3Sn–Ag composite film, which is induced by the giant magnetoresistance effect governed by the magnetic octupole induced momentum space spin splitting in the noncollinear antiferromagnet Mn3Sn. Moreover, compared to the complicated multilayer all-antiferromagnetic tunnel junction structures, the simple fabrication process of single-layer composite films in this work could facilitate the application of antiferromagnetic magnetoresistance devices.

APA, Harvard, Vancouver, ISO, and other styles

31

Sergeeva, G. G. "Underdoped cuprate antiferromagnet as a two-dimensional antiferromagnetic metal." Low Temperature Physics 31, no. 12 (December 2005): 1040–42. http://dx.doi.org/10.1063/1.2144455.

Full text

APA, Harvard, Vancouver, ISO, and other styles

32

Wang, L., S. G. Wang, Syed Rizwan, Q. H. Qin, and X. F. Han. "Magnetoresistance effect in antiferromagnet/nonmagnet/antiferromagnet multilayers." Applied Physics Letters 95, no. 15 (October 12, 2009): 152512. http://dx.doi.org/10.1063/1.3248223.

Full text

APA, Harvard, Vancouver, ISO, and other styles

33

Mao, Zhongquan, Xiaozhi Zhan, and Xi Chen. "Exchange bias in diluted-antiferromagnet/antiferromagnet bilayers." Journal of Physics D: Applied Physics 48, no. 2 (December 12, 2014): 025002. http://dx.doi.org/10.1088/0022-3727/48/2/025002.

Full text

APA, Harvard, Vancouver, ISO, and other styles

34

Safin, Ansar, Sergey Nikitov, Andrei Kirilyuk, Vasyl Tyberkevych, and Andrei Slavin. "Theory of Antiferromagnet-Based Detector of Terahertz Frequency Signals." Magnetochemistry 8, no. 2 (February 12, 2022): 26. http://dx.doi.org/10.3390/magnetochemistry8020026.

Full text

Abstract:

We present a theory of a detector of terahertz-frequency signals based on an antiferromagnetic (AFM) crystal. The conversion of a THz-frequency electromagnetic signal into the DC voltage is realized using the inverse spin Hall effect in an antiferromagnet/heavy metal bilayer. An additional bias DC magnetic field can be used to tune the antiferromagnetic resonance frequency. We show that if a uniaxial AFM is used, the detection of linearly polarized signals is possible only for a non-zero DC magnetic field, while circularly polarized signals can be detected in a zero DC magnetic field. In contrast, a detector based on a biaxial AFM can be used without a bias DC magnetic field for the rectification of both linearly and circularly polarized signals. The sensitivity of a proposed AFM detector can be increased by increasing the magnitude of the bias magnetic field, or by by decreasing the thickness of the AFM layer. We believe that the presented results will be useful for the practical development of tunable, sensitive and portable spintronic detectors of THz-frequency signals based of the antiferromagnetic resonance (AFMR).

APA, Harvard, Vancouver, ISO, and other styles

35

Shen, Kaijun, Maxim F. Gelin, Kewei Sun, and Yang Zhao. "Dynamics of a Magnetic Polaron in an Antiferromagnet." Materials 17, no. 2 (January 18, 2024): 469. http://dx.doi.org/10.3390/ma17020469.

Full text

Abstract:

The t-J model remains an indispensable construct in high-temperature superconductivity research, bridging the gap between charge dynamics and spin interactions within antiferromagnetic matrices. This study employs the multiple Davydov Ansatz method with thermo-field dynamics to dissect the zero-temperature and finite-temperature behaviors. We uncover the nuanced dependence of hole and spin deviation dynamics on the spin–spin coupling parameter J, revealing a thermally-activated landscape where hole mobilities and spin deviations exhibit a distinct temperature-dependent relationship. This numerically accurate thermal perspective augments our understanding of charge and spin dynamics in an antiferromagnet.

APA, Harvard, Vancouver, ISO, and other styles

36

Vallejo-Fernandez, Gonzalo, and Markus Meinert. "Recent Developments on MnN for Spintronic Applications." Magnetochemistry 7, no. 8 (August 11, 2021): 116. http://dx.doi.org/10.3390/magnetochemistry7080116.

Full text

Abstract:

There is significant interest worldwide to identify new antiferromagnetic materials suitable for device applications. Key requirements for such materials are: relatively high magnetocrystalline anisotropy constant, low cost, high corrosion resistance and the ability to induce a large exchange bias, i.e., loop shift, when grown adjacent to a ferromagnetic layer. In this article, a review of recent developments on the novel antiferromagnetic material MnN is presented. This material shows potential as a replacement for the commonly used antiferromagnet of choice, i.e., IrMn. Although the results so far look promising, further work is required for the optimization of this material.

APA, Harvard, Vancouver, ISO, and other styles

37

GOLINELLI, O., Th JOLICOEUR, and R. LACAZE. "HEISENBERG ANTIFERROMAGNETIC CHAIN of SPIN S=1." International Journal of Modern Physics C 05, no. 02 (April 1994): 259–61. http://dx.doi.org/10.1142/s0129183194000271.

Full text

Abstract:

The Heisenberg antiferromagnetic chain of spin 1 with the most general single ion anisotropy is numerically analyzed. Chains of length up to 22 sites are studied by a Lanczös method and up to 32 sites with a quantum Monte Carlo. Gaps, magnetic excitations, dynamical properties and magnetic field behaviour are obtained. The recent neutron scattering experiments on the quasi one-dimensional antiferromagnet NENP are fully explained by our results.

APA, Harvard, Vancouver, ISO, and other styles

38

Wang, Jian, Shinji Muraishi, Ji Shi, and Yoshio Nakamura. "Antiferromagnetic Layer Thickness Dependence of Exchange Bias in Sputter-Deposited Co/CoO/Co Trilayer." Materials Science Forum 675-677 (February 2011): 1263–66. http://dx.doi.org/10.4028/www.scientific.net/msf.675-677.1263.

Full text

Abstract:

We have used ferromagnet/antiferromagnet/ferromagnet sandwich structure to probe the antiferromagnetic layer thickness dependence of exchange bias in sputter-deposited Co/CoO/Co trilayer. The exchange coupling occurring at the upper ferromagnetic/antiferromagnetic interface is always found to be stronger than the one at the lower antiferromagnetic/ferromagnetic interface. The grain growth with increasing antiferromagnetic layer thickness can lead to a gradient of grain size distribution through the whole antiferromagnetic layer. Consequently, the relatively large grains at the upper interface would results in a rougher interface which we treat as structural defects and can significantly enhance exchange bias through domain state model. The slightly decrease of exchange coupling with increasing antiferromgnetic layer thickness indicates that the exchange bias is only governed by the grains that are thermally stable but whose anisotropy energy is low enough to be set.

APA, Harvard, Vancouver, ISO, and other styles

39

Sizanov, A. V., and A. V. Syromyatnikov. "Antiferromagnet with two coupled antiferromagnetic sublattices in a magnetic field." Journal of Physics: Condensed Matter 23, no. 14 (March 22, 2011): 146002. http://dx.doi.org/10.1088/0953-8984/23/14/146002.

Full text

APA, Harvard, Vancouver, ISO, and other styles

40

Sharmin, S., I. Umegaki, H. Tanaka, T. Ono, G. Tanaka, H. Nojiri, M. Fujisawa, et al. "Antiferromagnetic resonance modes for theS= 1/2 kagome antiferromagnet Cs2Cu3SnF12." Journal of Physics: Conference Series 302 (July 20, 2011): 012011. http://dx.doi.org/10.1088/1742-6596/302/1/012011.

Full text

APA, Harvard, Vancouver, ISO, and other styles

41

Asakura, Mihiro, Tomoya Higo, Takumi Matsuo, Ryota Uesugi, Daisuke Nishio‐Hamane, and Satoru Nakatsuji. "Observation of Omnidirectional Exchange Bias at All Antiferromagnetic Polycrystalline Heterointerface." Advanced Materials, March 26, 2024. http://dx.doi.org/10.1002/adma.202400301.

Full text

Abstract:

AbstractDue to promising functionalities that may dramatically enhance spintronics performance, antiferromagnets are the subject of intensive research for developing the next‐generation active elements to replace ferromagnets. In particular, the recent experimental demonstration of the tunneling magnetoresistance and electrical switching using chiral antiferromagnets has sparked expectations for the practical integration of antiferromagnetic materials into device architectures. To further develop the technology to manipulate the magnetic anisotropies in all‐antiferromagnetic devices, it is essential to realize exchange bias through the interface between antiferromagnetic multilayers. Here, we report our first observation on the omnidirectional exchange bias at an all‐antiferromagnetic polycrystalline heterointerface. Our experiment demonstrates that the interfacial energy causing the exchange bias between the chiral‐antiferromagnet Mn3Sn/collinear‐antiferromagnet MnN layers is comparable to those found at the conventional ferromagnet/antiferromagnet interface at room temperature. In sharp contrast with previous reports using ferromagnets, the magnetic field control of the unidirectional anisotropy is found to be omnidirectional due to the absence of the shape anisotropy in the antiferromagnetic multilayer. The realization of the omnidirectional exchange bias at the interface between polycrystalline antiferromagnets on amorphous templates, highly compatible with existing Si‐based devices, paves the way for developing ultra‐low power and ultra‐high speed memory devices based on antiferromagnets.This article is protected by copyright. All rights reserved

APA, Harvard, Vancouver, ISO, and other styles

42

Guo, Zongxia, Gregory Malinowski, Pierre Vallobra, Yi Peng, Yong Xu, Stéphane Mangin, Weisheng Zhao, Michel Hehn, and Boyu Zhang. "Ultrafast antiferromagnet rearrangement in Co/IrMn/CoGd trilayers." Chinese Physics B, June 1, 2023. http://dx.doi.org/10.1088/1674-1056/acda83.

Full text

Abstract:

Abstract Antiferromagnets offer great potential for high-speed data processing applications, as they can lead spintronic devices from a static storage and gigahertz frequency range to the terahertz range. However, their zero net magnetization makes them difficult to manipulate and detect. In recent years, there has been a lot of attention given to the ultrafast manipulation of magnetic order using ultra-short single laser pulses, but it remains unknown whether a similar scenario can be observed in antiferromagnets. In this work, we demonstrate the manipulation of antiferromagnets with a single femtosecond laser pulse in perpendicular exchange-biased Co/IrMn/CoGd trilayers. We studied the dual exchange bias interlayer interaction in quasi-static conditions and competition in ultrafast antiferromagnet rearrangement. Our results show that, compared to conventional ferromagnetic/antiferromagnetic systems, the IrMn antiferromagnet can be ultrafast and efficiently manipulated by the coupled CoGd ferrimagnetic layer, which paves the way for potential energy-efficient spintronic devices.

APA, Harvard, Vancouver, ISO, and other styles

43

Xiong, Danrong, Yuhao Jiang, Daoqian Zhu, Ao Du, Zongxia Guo, Shiyang Lu, Chunxu Wang, Qingtao Xia, Dapeng Zhu, and Weisheng Zhao. "Topological Magnetotransport and Electrical Switching of Sputtered Antiferromagnetic Ir₂₀Mn₈₀." Chinese Physics B, February 8, 2023. http://dx.doi.org/10.1088/1674-1056/acb9ec.

Full text

Abstract:

Abstract Topological magnetotransport in non-collinear antiferromagnets has attracted extensive attention due to the exotic phenomena such as large anomalous Hall effect (AHE), magnetic spin Hall effect, and chiral anomaly. The materials exhibiting topological antiferromagnetic physics are typically limited in special Mn3X family such as Mn3Sn and Mn3Ge. Exploring the topological magnetotransport in common antiferromagnetic materials widely used in spintronics will not only enrich the platforms for investigating the non-collinear antiferromagnetic physics, but also have great importance for driving the nontrivial topological properties towards practical applications. Here, we report remarkable AHE, anisotropic and negative parallel magnetoresistance in the magnetron-sputtered Ir20Mn80 antiferromagnet, which is one of the most widely used antiferromagnetic materials in industrial spintronics. The ab initio calculations suggest that the Ir4Mn16 (IrMn4) or Mn3Ir nanocrystals hold nontrivial electronic band structures, which may contribute to the observed intriguing magnetotransport properties in the Ir20Mn80. Further, we demonstrate the spin-orbit torque switching of the antiferromagnetic Ir20Mn80 by the spin Hall current of Pt. The presented results highlight a great potential of the magnetron-sputtered Ir20Mn80 film for exploring the topological antiferromagnet-based physics and spintronics applications.

APA, Harvard, Vancouver, ISO, and other styles

44

Kang, Jaimin, Jeongchun Ryu, Jong-Guk Choi, Taekhyeon Lee, Jaehyeon Park, Soogil Lee, Hanhwi Jang, Yeon Sik Jung, Kab-Jin Kim, and Byong-Guk Park. "Current-induced manipulation of exchange bias in IrMn/NiFe bilayer structures." Nature Communications 12, no. 1 (November 5, 2021). http://dx.doi.org/10.1038/s41467-021-26678-x.

Full text

Abstract:

AbstractThe electrical control of antiferromagnetic moments is a key technological goal of antiferromagnet-based spintronics, which promises favourable device characteristics such as ultrafast operation and high-density integration as compared to conventional ferromagnet-based devices. To date, the manipulation of antiferromagnetic moments by electric current has been demonstrated in epitaxial antiferromagnets with broken inversion symmetry or antiferromagnets interfaced with a heavy metal, in which spin-orbit torque (SOT) drives the antiferromagnetic domain wall. Here, we report current-induced manipulation of the exchange bias in IrMn/NiFe bilayers without a heavy metal. We show that the direction of the exchange bias is gradually modulated up to ±22 degrees by an in-plane current, which is independent of the NiFe thickness. This suggests that spin currents arising in the IrMn layer exert SOTs on uncompensated antiferromagnetic moments at the interface which then rotate the antiferromagnetic moments. Furthermore, the memristive features are preserved in sub-micron devices, facilitating nanoscale multi-level antiferromagnetic spintronic devices.

APA, Harvard, Vancouver, ISO, and other styles

45

Chen, Hongyu, Li Liu, Xiaorong Zhou, Ziang Meng, Xiaoning Wang, Zhiyuan Duan, Guojian Zhao, Han Yan, Peixin Qin, and Zhiqi Liu. "Emerging Antiferromagnets for Spintronics." Advanced Materials, January 6, 2024. http://dx.doi.org/10.1002/adma.202310379.

Full text

Abstract:

AbstractAntiferromagnets constitute promising contender materials for next‐generation spintronic devices with superior stability, scalability, and dynamics. Nevertheless, the perception of well‐established ferromagnetic spintronics underpinned by spontaneous magnetization seemed to indicate the inadequacy of antiferromagnets for spintronics—their compensated magnetization has been perceived to result in uncontrollable antiferromagnetic order and subtle magnetoelectronic responses. However, remarkable advancements have been achieved in antiferromagnetic spintronics in recent years, with consecutive unanticipated discoveries substantiating the feasibility of antiferromagnet‐centered spintronic devices. It is emphasized that, distinct from ferromagnets, the richness in complex antiferromagnetic crystal structures is the unique and essential virtue of antiferromagnets that can open up their endless possibilities of novel phenomena and functionality for spintronics. In this Perspective, the recent progress in antiferromagnetic spintronics is reviewed, with a particular focus on that based on several kinds of antiferromagnets with special antiferromagnetic crystal structures. The latest developments in efficiently manipulating antiferromagnetic order, exploring novel antiferromagnetic physical responses, and demonstrating prototype antiferromagnetic spintronic devices are discussed. An outlook on future research directions is also provided. It is hoped that this Perspective can serve as guidance for readers who are interested in this field and encourage unprecedented studies on antiferromagnetic spintronic materials, phenomena, and devices.

APA, Harvard, Vancouver, ISO, and other styles

46

Niu, Zhi Ping, and Xin Pei Wen. "Electrically controllable spin polarization in collinear antiferromagnetic junctions." Journal of Physics D: Applied Physics, May 10, 2023. http://dx.doi.org/10.1088/1361-6463/acd401.

Full text

Abstract:

Abstract Antiferromagnetic spintronics is a rapidly growing subfield of spintronics in condensed-matter physics and information technology. Electrical current in collinear antiferromagnetic materials is typically spin unpolarized, limiting the realization of antiferromagnetic spintronics effects. Here we study the transport in the collinear antiferromagnetic junctions by applying a transverse electric field $E_y$ to the antiferromagnets. The band structures of the collinear antiferromagnets may become spin-polarized when the combined time reversal and lattice translation symmetry is broken by $E_y$. The separation between spin-up and spin-down bands is controlled by $E_y$.Full spin polarization originating from spin-polarized states near the band gap's edges is observed at high exchange energy. In particular, as $E_y$ increases, the region capable of generating high spin polarization broadensdue to the increased separation between spin-up and spin-down bands. The amplitude and sign of spin polarization can be controlled by $E_y$. These characteristics indicate that collinear antiferromagnet materials are ideal for future spintronics applications.

APA, Harvard, Vancouver, ISO, and other styles

47

Huang, Lin, Liyang Liao, Hongsong Qiu, Xianzhe Chen, Hua Bai, Lei Han, Yongjian Zhou, et al. "Antiferromagnetic magnonic charge current generation via ultrafast optical excitation." Nature Communications 15, no. 1 (May 20, 2024). http://dx.doi.org/10.1038/s41467-024-48391-1.

Full text

Abstract:

AbstractNéel spin-orbit torque allows a charge current pulse to efficiently manipulate the Néel vector in antiferromagnets, which offers a unique opportunity for ultrahigh density information storage with high speed. However, the reciprocal process of Néel spin-orbit torque, the generation of ultrafast charge current in antiferromagnets has not been demonstrated. Here, we show the experimental observation of charge current generation in antiferromagnetic metallic Mn2Au thin films using ultrafast optical excitation. The ultrafast laser pulse excites antiferromagnetic magnons, resulting in instantaneous non-equilibrium spin polarization at the antiferromagnetic spin sublattices with broken spatial symmetry. Then the charge current is generated directly via spin-orbit fields at the two sublattices, which is termed as the reciprocal phenomenon of Néel spin-orbit torque, and the associated THz emission can be detected at room temperature. Besides the fundamental significance on the Onsager reciprocity, the observed magnonic charge current generation in antiferromagnet would advance the development of antiferromagnetic THz emitter.

APA, Harvard, Vancouver, ISO, and other styles

48

Kim, Jong Hyuk, Mi Kyung Kim, Ki Won Jeong, Hyun Jun Shin, Jae Min Hong, Jin Seok Kim, Kyungsun Moon, Nara Lee, and Young Jai Choi. "Spin-flip-driven reversal of the angle-dependent magnetic torque in layered antiferromagnetic Ca0.9Sr0.1Co2As2." Scientific Reports 12, no. 1 (July 27, 2022). http://dx.doi.org/10.1038/s41598-022-17206-y.

Full text

Abstract:

AbstractSpin-flip transition can occur in antiferromagnets with strong magnetocrystalline anisotropy, inducing a significant modification of the anisotropic magnetic properties through phase conversion. In contrast to ferromagnets, antiferromagnets have not been thoroughly examined in terms of their anisotropic characteristics. We investigated the magnetic-field and angle-dependent magnetic properties of Ising-type antiferromagnetic Ca0.9Sr0.1Co2As2 using magnetic torque measurements. An A-type antiferromagnetic order emerges below TN = 97 K aligned along the magnetically easy c-axis. The reversal of the angle-dependent torque across the spin-flip transition was observed, revealing the strong influence of the magnetocrystalline anisotropy on the magnetic properties. Based on the easy-axis anisotropic spin model, we theoretically generated torque data and identified specific spin configurations associated with the magnetic torque variation in the presence of a rotating magnetic field. Our results enrich fundamental and applied research on diverse antiferromagnetic compounds by shedding new light on the distinct magnetic features of the Ising-type antiferromagnet.

APA, Harvard, Vancouver, ISO, and other styles

49

El Kanj, Aya, Olena Gomonay, Isabella Boventer, Paolo Bortolotti, Vincent Cros, Abdelmadjid Anane, and Romain Lebrun. "Antiferromagnetic magnon spintronic based on nonreciprocal and nondegenerated ultra-fast spin-waves in the canted antiferromagnet α-Fe ₂ O ₃." Science Advances 9, no. 32 (August 11, 2023). http://dx.doi.org/10.1126/sciadv.adh1601.

Full text

Abstract:

Spin-waves in antiferromagnets hold the prospects for the development of faster, less power-hungry electronics and promising physics based on spin superfluids and coherent magnon condensates. For both these perspectives, addressing electrically coherent antiferromagnetic spin-waves is of importance, a prerequisite that has been so far elusive, because, unlike ferromagnets, antiferromagnets couple weakly to radiofrequency fields. Here, we demonstrate the detection of ultra-fast nonreciprocal spin-waves in the dipolar exchange regime of a canted antiferromagnet using both inductive and spintronic transducers. Using time-of-flight spin-wave spectroscopy on hematite (α-Fe 2 O 3 ), we find that the magnon wave packets can propagate as fast as 20 kilometers/second for reciprocal bulk spin-wave modes and up to 6 kilometers/second for surface spin-waves propagating parallel to the antiferromagnetic Néel vector. We lastly achieve efficient electrical detection of nonreciprocal spin-wave transport using nonlocal inverse spin-Hall effects. The electrical detection of coherent nonreciprocal antiferromagnetic spin-waves paves the way for the development of antiferromagnetic and altermagnet-based magnonic devices.

APA, Harvard, Vancouver, ISO, and other styles

50

Formisano, F., T. T. Gareev, D. I. Khusyainov, A. E. Fedianin, R. M. Dubrovin, P. P. Syrnikov, D. Afanasiev, et al. "Coherent THz spin dynamics in antiferromagnets beyond the approximation of the Néel vector." APL Materials 12, no. 1 (January 1, 2024). http://dx.doi.org/10.1063/5.0180888.

Full text

Abstract:

Controlled generation of coherent spin waves with highest possible frequencies and shortest possible wavelengths is a cornerstone of spintronics and magnonics. Here, using Heisenberg antiferromagnet RbMnF3, we demonstrate that laser-induced THz spin dynamics corresponding to pairs of mutually coherent counter-propagating spin waves with the wavevectors up to the edge of the Brillouin zone cannot be understood in terms of magnetization and antiferromagnetic (Néel) vectors, conventionally used to describe spin waves. Instead, we propose to model such spin dynamics using the spin correlation function. We derive a quantum-mechanical equation of motion for the latter and emphasize that unlike the magnetization and antiferromagnetic vectors the spin correlations in antiferromagnets do not exhibit inertia.

APA, Harvard, Vancouver, ISO, and other styles

Journal articles on the topic 'Antiferromagnet'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles