Дисертації з теми "Spin Injector"
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Van, Veenhuizen Marc Julien. "Investigation of the tunneling emitter bipolar transistor as spin-injector into silicon." Thesis, Massachusetts Institute of Technology, 2010. http://hdl.handle.net/1721.1/63011.
Повний текст джерелаCataloged from PDF version of thesis.
Includes bibliographical references (p. 185-196).
In this thesis is discussed the tunneling emitter bipolar transistor as a possible spin-injector into silicon. The transistor has a metallic emitter which as a spin-injector will be a ferromagnet. Spin-polarized electrons from the ferromagnet tunnel directly into the conduction band of the base of the transistor and are subsequently swept into the collector. The tunneling emitter bipolar transistor as a spin-injector allows for large spin-polarized currents and naturally overcomes the conductivity mismatch and Schottky barrier formation. In this work, the various aspects of the transistor are analyzed. The transfer of spin-polarization across the base-collector junction is simulated. The oxide MgO is considered as a tunnel barrier for the transistor. Electron spin resonance is proposed as a measurement technique to probe the spin-polarization injected into the collector. The fabrication of the transistors is discussed and the importance of the tunnel barrier for the device operation is fully analyzed. The observation of negative differential transconductance in the transistor is explained. A number of side- or unrelated studies are presented as well. A study on scattered and secondary electrons in e-beam evaporation is described. Spin-orbit coupling induced spin-interference of ring-structures is proposed as a spin-detector. A new measurement technique to probe bias dependent magnetic noise in magnetic tunnel junctions is proposed. Also, an IV fitting program that can extract the relative importance of the tunnel and Schottky barrier is discussed and employed to fit the base-emitter IV characteristics of the transistor. The development of several fabrication and experimental tools is described as well.
by Marc Julien van Veenhuizen.
Ph.D.
Gao, Xue. "Injection de spin dans les semiconducteurs et les matériaux organiques." Thesis, Université de Lorraine, 2019. http://www.theses.fr/2019LORR0059/document.
Повний текст джерелаSpintronics with semiconductors is very attractive as it can combine the potential of semiconductors with the potential of the magnetic materials. GaN has a long spin relaxation time, which could be of potential interest for spintronics applications. Organic spintronics is also very appealing because of the long spin lifetime of charge carriers in addition to their relatively low cost, flexibility, and chemical diversity. In this thesis, we investigate spin injection in spin LEDs containing either InAs/GaAs quantum dots or InGaN/GaN quantum wells. Moreover, we further study spin polarized transport in organic multiferroic tunnel junctions (OMFTJs). Firstly, we will show that the circular polarization of the light emitted by a LED containing a single layer of p-doped InAs/GaAs quantum dots (QDs) can reach about 18% under zero applied magnetic field. A clear correlation is established between the polarization degree of the emitted light and the perpendicular magnetization of the injector layer. The polarization reaches a maximum for an applied bias of 2.5V at 10K, which corresponds to an injected current of 6 µA. Also, we report a remarkable behavior of the polarization in the temperature region 60-80K. The interpretation of the bias and temperature dependence of the polarization is discussed in light of the competition between radiative recombination time τr and the spin relaxation time τs. In addition, significant efforts have been devoted to developing a perpendicular spin injector on GaN based materials to achieve spin injection without applying a magnetic field. Firstly, the growth of MgO has been investigated at various growth temperatures. Then, we studied the growth of either Fe or Co on MgO/GaN. In contrast to Fe/MgO, the Co/MgO spin injector yields a clear perpendicular magnetic anisotropy. In addition, ab-initio calculations have been performed to understand the origin of the perpendicular magnetic anisotropy at the Co/MgO(111) interface. Finally, we investigate multiferroic tunnel junctions (MFTJs) based on organic PVDF barriers doped with Fe3O4 nano particles. The organic MFTJs have recently attracted much attention since they can combine advantages of spintronics, organic and ferroelectric electronics. We report on the successful fabrication of La0.6Sr0.4MnO3/PVDF:Fe3O4/Co OMFTJ, where the poly(vinylidene fluoride) (PVDF) organic barrier has been doped with ferromagnetic Fe3O4 nanoparticles. By changing the polarization of the ferroelectric PVDF, the tunneling process in OMFTJ can be switched either through the LSMO/PVDF/Co part (positive polarization) or through the Fe3O4/PVDF/Co part (negative polarization). This corresponds to a reversal of tunneling magnetoresistance (TMR) from +10% to -50%, respectively. Our study shows that the doping of OMFTJs with magnetic nanoparticles can create new functionalities of organic spintronic devices by the interplay of nanoparticle magnetism with the ferroelectricity of the organic barrier
Gao, Xue. "Injection de spin dans les semiconducteurs et les matériaux organiques." Electronic Thesis or Diss., Université de Lorraine, 2019. http://www.theses.fr/2019LORR0059.
Повний текст джерелаSpintronics with semiconductors is very attractive as it can combine the potential of semiconductors with the potential of the magnetic materials. GaN has a long spin relaxation time, which could be of potential interest for spintronics applications. Organic spintronics is also very appealing because of the long spin lifetime of charge carriers in addition to their relatively low cost, flexibility, and chemical diversity. In this thesis, we investigate spin injection in spin LEDs containing either InAs/GaAs quantum dots or InGaN/GaN quantum wells. Moreover, we further study spin polarized transport in organic multiferroic tunnel junctions (OMFTJs). Firstly, we will show that the circular polarization of the light emitted by a LED containing a single layer of p-doped InAs/GaAs quantum dots (QDs) can reach about 18% under zero applied magnetic field. A clear correlation is established between the polarization degree of the emitted light and the perpendicular magnetization of the injector layer. The polarization reaches a maximum for an applied bias of 2.5V at 10K, which corresponds to an injected current of 6 µA. Also, we report a remarkable behavior of the polarization in the temperature region 60-80K. The interpretation of the bias and temperature dependence of the polarization is discussed in light of the competition between radiative recombination time τr and the spin relaxation time τs. In addition, significant efforts have been devoted to developing a perpendicular spin injector on GaN based materials to achieve spin injection without applying a magnetic field. Firstly, the growth of MgO has been investigated at various growth temperatures. Then, we studied the growth of either Fe or Co on MgO/GaN. In contrast to Fe/MgO, the Co/MgO spin injector yields a clear perpendicular magnetic anisotropy. In addition, ab-initio calculations have been performed to understand the origin of the perpendicular magnetic anisotropy at the Co/MgO(111) interface. Finally, we investigate multiferroic tunnel junctions (MFTJs) based on organic PVDF barriers doped with Fe3O4 nano particles. The organic MFTJs have recently attracted much attention since they can combine advantages of spintronics, organic and ferroelectric electronics. We report on the successful fabrication of La0.6Sr0.4MnO3/PVDF:Fe3O4/Co OMFTJ, where the poly(vinylidene fluoride) (PVDF) organic barrier has been doped with ferromagnetic Fe3O4 nanoparticles. By changing the polarization of the ferroelectric PVDF, the tunneling process in OMFTJ can be switched either through the LSMO/PVDF/Co part (positive polarization) or through the Fe3O4/PVDF/Co part (negative polarization). This corresponds to a reversal of tunneling magnetoresistance (TMR) from +10% to -50%, respectively. Our study shows that the doping of OMFTJs with magnetic nanoparticles can create new functionalities of organic spintronic devices by the interplay of nanoparticle magnetism with the ferroelectricity of the organic barrier
Zhou, Ziqi. "Optical and Electrical Properties of Two-Dimensional Materials." Electronic Thesis or Diss., Université de Lorraine, 2021. http://www.theses.fr/2021LORR0141.
Повний текст джерелаTwo-dimensional (2D) semiconductor materials exhibit overwhelming electrical, optical, magnetic, thermal and other advantages, which enables their great potential applications in ultra-thin, transparent and highly integrated optoelectronic devices. Searching new two-dimensional materials and exploring their optimal performance, as well as expanding the practical application of two-dimensional materials have been the cores of the researches of two-dimensional materials. This thesis focuses on the vertical magnetic control of the CoFeB film on a large-area single-layer MoS₂ film, which could expand the potential of two-dimensional materials in spin optical detectors, the Polarized Photodetection (anisotropy) based on noval two-dimensional semiconductor GeAs, and the optical characterizations of group IV-VI compounds like SnS and ZnSnS alloys. This paper introduces them in detail through the following three parts: 1. We research the fabrication of the Ta/CoFeB/MgO structures with large perpendicular magnetic anisotropies (PMA) on the full coverage MoS₂ monolayers. By optimizing the thickness of the CoFeB layer and the annealing temperature, a large perpendicular interface anisotropy energy of 0.975 mJ/m² has been obtained at the CoFeB/MgO interface. By analyzing the structural and the chemical properties of the heterostructure, it is found that the insertion of MgO between the ferromagnetic metal (FM) and the 2D material can effectively block the diffusion of the FM atoms into the 2D material, and that the Ta layer plays a critical role to efficiently absorb B atoms from the CoFeB layer to establish the PMA. From the results of ab initio calculations, the MgO thickness can be tuned to modify the MoS₂ band structure, from an indirect bandgap with 7 MLs MgO layers to a direct bandgap with 3 MLs MgO layers. The proximity effect induced by Fe results in a splitting of 10 meV in the valence band at the Γ point of the 3MLs MgO structure while it is negligible for the 7MLs MgO structure. 2. we research the anisotropic optical characterization of a group IV-V compound, Germanium Arsenic (GeAs), with anisotropic monoclinic structure. The in-plane anisotropic optical nature of GeAs crystal is further investigated by the polarization-resolved absorption spectroscopy (400-2000 nm) and the polarization-sensitive photodetectors. In the visible-to-near-infrared range, the 2D GeAs nanoflakes demonstrate the distinct perpendicular optical reversal with an angle of 75~80 degrees on both of the linear dichroism and the polarization-sensitive photodetection. Obvious anisotropic features and the high dichroic ratio of Ipmax/Ipmin ~ 1.49 at 520 nm and Ipmax/Ipmin ~ 4.4 at 830 nm are measured by the polarization-sensitive photodetection. The polarization-dependent photocurrent mapping implied that the polarized photocurrent mainly occurred at the Schottky photodiodes at the electrode/GeAs interface. 3. We research optical characterizations of group-IV-VI compounds like SnS and ZnSnS alloys. SnS nanosheets exhibit carrier mobility of 37.75 cm²·V⁻¹·s⁻¹, photoresponsivity of 310.5 A/W and external quantum efficiency of 8.56×104% at 450 nm. Optical absorption around the absorption edge presents obvious polarization sensitivity with the highest optical absorption dichroic ratio of 3.06 at 862 nm. Due to the anisotropic optical absorption, the polarized photocurrent appears upon the periodic change affected by the polarized direction of the incident light at 808 nm. The ZnSnS alloys combine the advantageous optical parameters of SnS and ZnS₂, which belong to the direct band structure of n-type 2D semiconductors. The carrier mobility of the alloy is 65 cm² V⁻¹ S⁻¹ and the on/off ratio under white-LED illumination is as high as 51
Aziz, A. "Spin injection into semiconductors." Thesis, University of Cambridge, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.596232.
Повний текст джерелаMooser, Sebastian Thomas. "Spin injection, spin transport and spin-charge conversion in organic semiconductors." Thesis, University of Cambridge, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.608211.
Повний текст джерелаLin, Ran. "Organic spintronic devices utilizing spin-injection, spin-tunneling and spin-dependent transport." Diss., University of Iowa, 2013. https://ir.uiowa.edu/etd/5015.
Повний текст джерелаGarzon, Samir Y. "Spin injection and detection in copper spin valve structures." College Park, Md. : University of Maryland, 2005. http://hdl.handle.net/1903/2192.
Повний текст джерелаThesis research directed by: Physics. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.
Dash, Saroj Prasad. "Towards spin injection into silicon." Stuttgart Max-Planck-Institut für Metallforschung, 2007. http://nbn-resolving.de/urn:nbn:de:bsz:93-opus-33304.
Повний текст джерелаSeverac, Childerick Henri Louis. "Spin injection into high temperature superconductor." Thesis, University of Birmingham, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.369295.
Повний текст джерелаChen, Peifeng. "Spin polarized tunneling and spin injection in Fe-GaAs hybrid structures." [S.l.] : [s.n.], 2006. http://deposit.ddb.de/cgi-bin/dokserv?idn=981364837.
Повний текст джерелаBeardsley, Jonas T. "Charge-Spin Transport Correlation in Local Electrical Spin Injection in Silicon." The Ohio State University, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=osu1417777678.
Повний текст джерелаFrougier, Julien. "Toward Spin-LED and Spin-VECSEL operations at magnetic remanence." Thesis, Paris 11, 2014. http://www.theses.fr/2014PA112175/document.
Повний текст джерелаThis Ph.D Thesis proposes to explore a new paradigm of spin-information propagation over very long distances after encoding on coherent light polarization. The main objective of this manuscript is to provide a detailed study of spin-injection into III-V semiconductor based opto-electronic devices with vertical geometries. To achieve this goal, we focus on the study of optical and electrical spin-injection in III-V semiconductor based Light Emitting Diodes (LEDs) and Vertical External Cavity Surface Emitting Lasers (VECSELs). Our investigations and results are presented on three axes.The first part regroups a state-of-the-art of spin-injection into semiconductors optoelectronic devices and focuses on the physical phenomena engaged in the conversion of a spin accumulation into light polarization information. A discussion on spin-injection and spin-transport into III-V semiconductor structures is followed by a more device-oriented review on spin-injection in LEDs and VCSELs.The second axis is articulated around our experimental work on the development and the optimization on III-V semiconductors LEDs of an ultra-thin MgO/CoFeB/Ta spin-injector with perpendicular magnetization at magnetic remanence. We focus on the MgO tunnel barrier optimization for maximizing the spin-injection efficiency and further detailed the development and the characterization of the spin-injector with perpendicular magnetization at remanence.Finally, the third part contains the main work of this Ph.D thesis. It is fully dedicated to our experimental research on spin-injection in Vertical External Cavity Surface Emitting Laser structures. A vectorial model allowing the theoretical understanding of polarization selection in spin-injected VECSELs is first introduced. Next, we report the birefringence measurement of a VECSEL designed for optical pumping using an original frequency detuning measurement between the two orthogonal TE- and TM-modes. Afterward, our observations and results on optical spin-injection in VECSELs are displayed, analyzed and commented. The study is farther extended to the measurement of the system's characteristic lifetimes using Time Resolved Photo-Luminescence in order to evaluate the spin-information conversion efficiency. Finally the preliminary results on electrical spin-injection experiment are presented
Venkataraman, Karthik (Karthik Raman). "Spin injection and manipulation in organic semiconductors." Thesis, Massachusetts Institute of Technology, 2011. http://hdl.handle.net/1721.1/69795.
Повний текст джерелаCataloged from PDF version of thesis. Vita.
Includes bibliographical references (p. 141-155).
The use of organic semiconductors to enable organic spintronic devices requires the understanding of transport and control of the spin state of the carriers. This thesis deals with the above issue, focusing on the interface between the organic semiconductor and the spin source. The morphology of the organic molecule at the interface is shown to play a dominant role in this study, influencing spin injection. The interface molecule morphology affects the form of interaction between the organic molecule and the ferromagnet. This interaction ranges from a weak Van der Waals' to a chemical interaction leading to charge transfer, hybridization and other interface chemistry. As a result, the spin-dependent density of states is modified, influencing the spin injection process. The first part of the thesis focuses on identifying the interface properties between the ferromagnet and the organic semiconductor, rubrene. This is performed in a vertical organic junction geometry using different interface characterization tools. The growth morphology of the rubrene molecule is shown to influence the electronic coupling between the molecule and the ferromagnet. This has a pronounced effect on the spin injection efficiency and the magnetoresistance signals in the devices. The complex nature of the top interface is dealt with in detail. These studies provide insights on the importance of tailoring the interface properties to control and realize optimum behavior. As an alternative to conventional ferromagnets, a spin-filter material, europium sulphide, is demonstrated as a spin-polarized source. Spin-filter materials have shown the possibility to inject spin-polarized electrons into the organic semiconductor at higher voltage bias. This knowledge encouraged to seek organic spin-filter materials. Understanding the importance of molecule morphology from the work on rubrene, the second part of the thesis involved the study on a new class of organic materials called the phenalenyl compounds. Study using the compound, Zinc methyl phenalenyl, was initiated that showed large magnetoresistance signals of 50% at 4.2 K to 20% at close to room temperature. The origin of this magnetoresistance is attributed to a new interface phenomena described by the spin-filtering effect. The interface molecule morphology is found to play a very important role at the interface inducing an antiferromagnetic state and dominating the device physics. This technique opens up a new approach to engineer the interface and realize new functional devices without worrying about the bulk disorder of the organic film. This thesis thus shows the feasibility of tuning the property of the interface using tailor-made molecules to realize new functional devices at room temperature that can lead to development of the field and technological applications.
by Karthik V. Raman.
Ph.D.
Lombez, Laurent. "Injection optique et injection électrique de spin dans des nanostructures semiconductrices." Toulouse, INSA, 2007. http://eprint.insa-toulouse.fr/archive/00000265/.
Повний текст джерелаThis thesis describes photoluminescence and electroluminescence spectroscopy studies of the spin properties of semiconductors nanostructures for applications in spin-electronics. We analyze the electronic spin properties in dilute nitride semiconductors such as GaAsN bulk and InGaAsN / GaAs quantum wells. We observe, at room temperature, a slow decay of the circular polarization as well as a strong spin polarization of the conduction band electrons. The origins of these result is linked to the spin dependant recombination mechanism of the electron in the conduction band with deep paramagnetic centers. Moreover, we study the problem of the electrical spin injection in hybrid metal / semiconducteur structures (spin-LED). The spin injection is realized from a Cobalt layer through an oxide tunnel barrier and it is detected by quantum well electroluminescence. Furthermore, after characterizing the spin dynamics in p-doped quantum dots by photoluminescence spectroscopy and demonstrating the major role of the hyperfin interaction, we realize an efficient electrical spin injection into quantum dots
Hankinson, John H. "Spin dependent current injection into epitaxial graphene nanoribbons." Diss., Georgia Institute of Technology, 2015. http://hdl.handle.net/1853/53884.
Повний текст джерелаUPPALURI, SIRISHA. "SPIN INJECTION ACROSS A FERROMAGNET / SEMICONDUCTING NANOWIRE INTERFACE." University of Cincinnati / OhioLINK, 2005. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1119298910.
Повний текст джерелаPatibandla, Sridhar. "Spin transport studies in nanoscale spin valves and magnetic tunnel junctions." VCU Scholars Compass, 2008. http://scholarscompass.vcu.edu/etd/1611.
Повний текст джерелаFrangou, Lamprini. "Injection, transmission et détection de spin dans les matériaux antiferromagnétiques." Thesis, Université Grenoble Alpes (ComUE), 2017. http://www.theses.fr/2017GREAY079/document.
Повний текст джерелаAntiferromagnetic spintronics is an emerging research field in the area of information technology that exploits the unique combination of properties of antiferromagnets. It is their high excitation frequency, robustness against external fields, zero net magnetization and possibility of generating large magneto-transport effects that makes them so interesting. Spin transfer, spin-orbit coupling and spin caloritronics constitute the phenomena that have shaped much of the recent research and development towards pure antiferromagnetic spintronics. Here we investigate spin transfer torque and spin pumping in both metallic and insulating antiferromagnets by means of ferromagnetic resonance technique, in ferromagnetic spin injector – NiFe, CoFeB / (spin conductor – Cu) / antiferromagnetic spin sink – IrMn, NiFeOx, NiO trilayers. Temperature dependence measurements of the ferromagnetic relaxation revealed a novel spin pumping effect associated to the linear fluctuations at the magnetic phase transition of the antiferromagnet, regardless its electronic state and the nature of the spin transport. This opens new ways towards more efficient spin pumping, while providing at the same time a versatile method to probe the critical temperature of ultrathin films with zero net magnetization. Next, in an effort to probe linear as well as non-linear fluctuations in the antiferromagnet we conducted electrical measurements in spin Hall geometry. A novel non-monotonous temperature dependence of transverse dc voltage was sometimes observed, mostly associated to the properties of a specific ferromagnet: Permalloy, unrelated to spin rectification effects. These findings add to a growing body of literature on spin current absorption, highlighting the ability of ferromagnets to act as spin current detectors, in phenomena involving magnetization dynamics. Finally, we used exchange bias to investigate and subsequently engineer the magnetic and electric properties of various antiferromagnets intended for diverse spintronic applications including reading via tunneling anisotropic magnetoresistance
Liefeith, Lennart-Knud [Verfasser]. "Spin injection through metal-semiconductor contacts / Lennart-Knud Liefeith." München : Verlag Dr. Hut, 2016. http://d-nb.info/1122524498/34.
Повний текст джерелаMansell, Rhodri. "Spin injection, transport and detection in GaAs-based heterostructures." Thesis, University of Cambridge, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.608705.
Повний текст джерелаMoorsom, Timothy. "Electron transfer and spin injection in C60-ferromagnetic composites." Thesis, University of Leeds, 2016. http://etheses.whiterose.ac.uk/15569/.
Повний текст джерелаGrollier, Julie. "Renversement d'aimantation par injection d'un courant polarisé en spin." Paris 6, 2003. https://tel.archives-ouvertes.fr/tel-00003941.
Повний текст джерелаZhu, Lei. "Spin injection and transport in semiconductor and metal nanostructures." Diss., [La Jolla] : University of California, San Diego, 2009. http://wwwlib.umi.com/cr/ucsd/fullcit?p3378526.
Повний текст джерелаTitle from first page of PDF file (viewed October 22, 2009). Available via ProQuest Digital Dissertations. Vita. Includes bibliographical references.
Lesne, Edouard. "Non-Equilibrium Spin Accumulation Phenomena at the LaAlO3/SrTiO3(001) Quasi-Two-Dimensional Electron System." Thesis, Paris 6, 2015. http://www.theses.fr/2015PA066417/document.
Повний текст джерелаWe investigated the generation, manipulation, and detection of non-equilibrium spin accumulation in the nonmagnetic LaAlO3/SrTiO3 (LAO/STO) oxide heterostructure, which is the host of a quasi-two-dimensional electron system (q2DES). In electrical tunneling spin injection experiments, we made use of the (three-terminal) Hanle effect to probe the magnitude of spin accumulation at Co/LAO/STO interfaces. We report on large amplification effects of the spin signal, ascribed to spin-conserving sequential tunneling processes via localized electronic states of enhanced spin lifetimes. A substantial modulation of the spin signal, by electrostatic field-effect, evidences the successful generation of spin accumulation inside the q2DES. We further resorted to ferromagnetic resonance experiments in a cavity to adiabatically pump a spin current from a permalloy layer toward the LAO/STO interface. We find that the generated spin current is converted into a sizeable planar charge current within the q2DES. This is attributed to an inverse Edelstein effect deriving from a Rashba-like spin-orbit interaction, both of which are efficiently modulated by electrostatic field-effect. Hence, our findings expand the general field of interest from planar charge transport to the exploration of spin-dependent phenomena in a prototypical nonmagnetic conducting oxide channel. Additionally, we have also demonstrated that the critical thickness threshold for the onset of a q2DES at LAO/STO interfaces can be reduced to a single unit cell of LAO when resorting to various metal capping layers. It opens up a new field of investigation to tentatively identify the potential mechanisms driving the formation of the q2DES
Grenet, Louis. "Injection de spins dans les semi-conducteurs." Phd thesis, Grenoble, 2010. http://tel.archives-ouvertes.fr/tel-00508923.
Повний текст джерелаGrenet, Louis. "Injection de spins dans les semi-conducteurs." Phd thesis, Grenoble, 2010. http://www.theses.fr/2010GRENY010.
Повний текст джерелаSpin injection into semiconductors is a key point of spintronics, which aims at using spin of electron as a degree of freedom. This work deals with spin injection l'rom a ferromagnetic electrode into semiconductor through a tunnel ballier without applying a magnetic tield. Spin polarization of the current is optically detected, that requires an out-of-plane magnetization of the electrodes. This work is thus structured in two pmts. The tirst section deals withl fabrication of oxide/ferromagnetic metal heterostructures for spin injection into GaAs and Si. Growth of MgO/FePt by molecular beam epitaxy on GaA and of AhOJ/CoPt by sputtering on Si are described. The study of the magnetic, structural and transport properties of such layers prove the possibility , obtaining thin layers for spin injection in different semiconducting materials. The second part of this work focuses on spin polarized transport in Silico Spin injection into this material without applying a external magnetic tilm is thus demonstrated t()r the tirst time thanks to electroluminescence measurements. The analysis of the light emitted by a SiGe quantum weil embedded in a Si diode shows an optical polmization of about 3% which is caused by the spin polarization of the injected current
Lesne, Edouard. "Non-Equilibrium Spin Accumulation Phenomena at the LaAlO3/SrTiO3(001) Quasi-Two-Dimensional Electron System." Electronic Thesis or Diss., Paris 6, 2015. https://accesdistant.sorbonne-universite.fr/login?url=https://theses-intra.sorbonne-universite.fr/2015PA066417.pdf.
Повний текст джерелаWe investigated the generation, manipulation, and detection of non-equilibrium spin accumulation in the nonmagnetic LaAlO3/SrTiO3 (LAO/STO) oxide heterostructure, which is the host of a quasi-two-dimensional electron system (q2DES). In electrical tunneling spin injection experiments, we made use of the (three-terminal) Hanle effect to probe the magnitude of spin accumulation at Co/LAO/STO interfaces. We report on large amplification effects of the spin signal, ascribed to spin-conserving sequential tunneling processes via localized electronic states of enhanced spin lifetimes. A substantial modulation of the spin signal, by electrostatic field-effect, evidences the successful generation of spin accumulation inside the q2DES. We further resorted to ferromagnetic resonance experiments in a cavity to adiabatically pump a spin current from a permalloy layer toward the LAO/STO interface. We find that the generated spin current is converted into a sizeable planar charge current within the q2DES. This is attributed to an inverse Edelstein effect deriving from a Rashba-like spin-orbit interaction, both of which are efficiently modulated by electrostatic field-effect. Hence, our findings expand the general field of interest from planar charge transport to the exploration of spin-dependent phenomena in a prototypical nonmagnetic conducting oxide channel. Additionally, we have also demonstrated that the critical thickness threshold for the onset of a q2DES at LAO/STO interfaces can be reduced to a single unit cell of LAO when resorting to various metal capping layers. It opens up a new field of investigation to tentatively identify the potential mechanisms driving the formation of the q2DES
Zhang, Tiantian. "Injection de spin dans des systèmes à base de semiconducteurs III-V en vue de nouveaux composants spintroniques." Thesis, Toulouse, INSA, 2014. http://www.theses.fr/2014ISAT0005/document.
Повний текст джерелаSpintronics of semiconductors aims at using carrier spins as supplementary means of information transport. Thiswould lead to components showing extended functionalities. This thesis work is dedicated to the study of injectionand manipulation of electron spin in semiconductors, which are the basis of any spintronic application. In a first stepwe demonstrate the high efficiency of CoFeB/MgO/GaAs - based spin injectors. Circular polarization degrees of electroluminescence over 20% are measured on spin polarized LEDs (SpinLEDs) at 0.8 T and 25 K. Comparison betweensputtering- and MBE- grown spin injectors has shown similar results. In both case, spin injection efficiency is increasedby thermal annealing of the sample, in the range 300 − 350◦C. Indeed, annealing improves the quality of CoFeB/MgOinterface, and induces the crystallization of CoFeB above 300◦C. A higher stability of spin injection with current injectionis found when the tunnel barrier is grown by sputtering. This is due to the MgO/GaAs interface characteristicswhich is related to the growth technique. In a second step, we demonstrate spin injection without external appliedmagnetic field, through an ultra-thin (a few atomic layers) CoFeB electrode, taking advantage of the perpendicular magnetic anisotropy of the layer which leads to a remanant magnetization along the growth axis. For the first time in this configuration, circular polarization degrees of electroluminescence of about 20% are measured at 25 K at zero magnetic field. In a third step, due to the crucial role it may play in electrical injection, electron spin dynamics in high energy L-valleys is investigated. Using polarization resolved excitation photoluminescence in the range 2.8-3.4 eV, we observe that a fraction of photogenerated spin polarization is preserved when electrons are scattered hundreds of meV down to Γ valley. Spin relaxation time in L valleys is estimated to 200 fs. Finally we investigate electron and spin properties of GaAsBi dilute bismide alloy. We observe that the bandgap energy is reduced by 85meV/%Bi when Bi element is introduced into GaAs matrix. Moreover, the electron Land´e factor is about twice the one in GaAs for a 2.2% Bi composition. These features are evidence of the strong perturbation of host states and spin-orbit interaction enhancement
Dash, Saroj Prasad [Verfasser]. "Towards spin injection into silicon / vorgelegt von Saroj Prasad Dash." Stuttgart : Max-Planck-Inst. für Metallforschung, 2007. http://d-nb.info/995385386/34.
Повний текст джерелаHickey, M. C. "Spin injection from magnetic thin films into InGaAs quantum wells." Thesis, University of Cambridge, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.603996.
Повний текст джерелаLin, Weiwei, Kai Chen, Shufeng Zhang, and C. L. Chien. "Enhancement of Thermally Injected Spin Current through an Antiferromagnetic Insulator." AMER PHYSICAL SOC, 2016. http://hdl.handle.net/10150/614754.
Повний текст джерелаNoel, Paul. "Dynamical spin injection and spin to charge current conversion in oxide-based Rashba interfaces and topological insulators." Thesis, Université Grenoble Alpes (ComUE), 2019. http://www.theses.fr/2019GREAY062.
Повний текст джерелаUsing a ferromagnetic layer has been the first method to obtain and detect spin currents, allowing to modify the magnetization state of an adjacent layer using spin transfer torque. However, in recent years, an alternative way to manipulate spin currents has been proposed. An emerging field of spintronics, called spin-orbitronics, exploits the interplay between charge and spin currents enabled by the spin-orbit coupling (SOC) in non-magnetic systems. An efficient current conversion can be obtained through the Spin Hall Effect in heavy metals such as Platinum or Tantalum. The conversion can also be obtained by exploiting the Edelstein Effect in Rashba interfaces and topological insulators.The spin to charge conversion by means of Inverse Edelstein Effect and inverse Spin Hall Effect can be studied by the spin pumping by ferromagnetic resonance technique. This manuscript present these two conversion mechanisms as well as the technique that was used to measure them, which is based on an electrical detection of the ferromagnetic resonance. Results on the spin to charge current conversion obtained in metals, oxide-based Rashba interfaces and topological insulators will be presented. Among these systems we have demonstrated the possibility to tune the conversion efficiency by using a gate voltage in a two-dimensional electron gas at the surface of an oxide SrTiO3. Moreover it is possible to tune this effect, a remanent way, thanks to the ferroelectricity obtained in SrTiO3 at cryogenic temperatures.Other studied systems such as topological insulators HgTe and Sb2Te3 also have promising properties for an efficient spin to charge current conversion at room temperature. In particular we showed than in HgTe by using a thin HgCdTe protective layer, it is possible to obtain a spin to charge current conversion efficiency one order of magnitude larger than in Pt.These results suggest that stwo dimensional electron gases at oxide interfaces and topological insulators have a strong potential for the efficient detection of spin currents for possible beyond CMOS applications
Jain, Abhinav. "Injection de spin dans le germanium : de l'injecteur ferromagnétique métallique à l'injecteur semiconducteur (Ge,Mn)." Phd thesis, Université de Grenoble, 2011. http://tel.archives-ouvertes.fr/tel-00647310.
Повний текст джерелаKim, Yong-Jae. "Electrical injection and detection of spin polarization in InSb/ferromagnet nanostructures." Diss., Virginia Tech, 2012. http://hdl.handle.net/10919/28589.
Повний текст джерелаPh. D.
Grollier, Julie. "Renversement d' aimantation par injection d' un courant polarise en spin." Phd thesis, Université Pierre et Marie Curie - Paris VI, 2003. http://tel.archives-ouvertes.fr/tel-00003941.
Повний текст джерелаEndres, Bernhard [Verfasser], Günther [Akademischer Betreuer] Bayreuther, and Dominique [Akademischer Betreuer] Bougeard. "Spin injection into GaAs / Bernhard Endres. Betreuer: Günther Bayreuther ; Dominique Bougeard." Regensburg : Universitätsbibliothek Regensburg, 2013. http://d-nb.info/1038580056/34.
Повний текст джерелаLaribi, Sana. "Déplacement de parois magnétiques par injection d'un courant polarisé en spin." Paris 6, 2008. http://www.theses.fr/2008PA066615.
Повний текст джерелаAlharthi, Sami S. "Nonlinear dynamics of solitary and optically-injected spin vertical-cavity lasers." Thesis, University of Essex, 2016. http://repository.essex.ac.uk/16632/.
Повний текст джерелаBergeson, Jeremy D. "Spin-dependent transport phenomena in organic semiconductors." Columbus, Ohio : Ohio State University, 2007. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1167674229.
Повний текст джерелаPo-Hsiang, Wang. "Magneto-optical studies of optical spin injection in InAs quantum dot structures." Thesis, Linköpings universitet, Funktionella elektroniska material, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-75263.
Повний текст джерелаWang, N. Y. N. "Optical spin injection and XMCD in ultrathin magnetic films deposited on GaAs." Thesis, University of Salford, 2009. http://usir.salford.ac.uk/26959/.
Повний текст джерелаHu, Kaige. "Optically-injected spin current and its scattering effect in semiconductor quantum wells." Click to view the E-thesis via HKUTO, 2007. http://sunzi.lib.hku.hk/HKUTO/record/B39557571.
Повний текст джерелаGuan, Wei. "Ultrathin films on semiconductor substrates: growth, magneto-optical characteristics and spin injection." Thesis, University of Salford, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.490413.
Повний текст джерелаHu, Kaige, and 胡凱歌. "Optically-injected spin current and its scattering effect in semiconductor quantum wells." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2007. http://hub.hku.hk/bib/B39557571.
Повний текст джерелаLi, Bin. "Electrical bistability in organic semiconductors and spin injection using organic magnetic semiconductor." The Ohio State University, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=osu1334864514.
Повний текст джерелаHill, Cory J. McGill T. C. "Investigation of spin injection and optical imaging with scanning probe microscopy techniques /." Diss., Pasadena, Calif. : California Institute of Technology, 2001. http://resolver.caltech.edu/CaltechETD:etd-12172004-153816.
Повний текст джерелаPirkle, Wesley C. "Nontraditional architectures and spin processes in organic light emitting devices." Connect to this title online, 2005. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1111626474.
Повний текст джерелаTitle from first page of PDF file. Document formatted into pages; contains xiv, 139 p.; also includes graphics (some col.) Includes bibliographical references (p. 132-139). Available online via OhioLINK's ETD Center
Lerescu, Alexandru Ionuţ. "Spin and charge transport in a gated two dimensional electron gas." [S.l. : Groningen : s.n. ; University Library Groningen] [Host], 2007. http://irs.ub.rug.nl/ppn/304671568.
Повний текст джерелаLiu, Yanwei. "A study of magnetic ultrathin films on GaAs and optically excited spin injection." Thesis, University of Salford, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.490537.
Повний текст джерела