瞬态光栅系统的建设
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摘要
瞬态自旋光栅是近几年重新发展起来的超快激光光谱技术,是半导体材料中自旋输运特性研究的强有力的实验技术。我们介绍了瞬态光栅系统原理及光路的建设,包括瞬态光栅的产生与探测。并且采用了外差探测法(HeterodyneDetection)大大提高信噪比,能得到平滑的实验信号。利用我们建设的瞬态光栅系统,研究了(110)方向生长的本征GaAs/AlGaAs单量子阱中自旋输运特性,在室温下测得了电子自旋的扩散常数和双极扩散常数。进一步测量电子自旋扩散常数和激发功率的关系发现,随着激发功率的增加,自旋扩散常数D_s先是随着激发功率的增加而减小;当激发功率达到10mW时后,自旋扩散常数不随激发功率变化。测量双极扩散常数D_c和激发功率的关系发现,双极扩散常数不随激发功率的增加而变化。
Spintronics or spin-based electronics,which has been paid intense attentions in the field of Condensed Matter Physics and Information Sciences,aims to exploit the spin degree of freedom of the electron to develop a new generation of electronic devices.Two of the important issues on realizing the spintronics device are how to prolong the spin relaxation time and the spin diffusion length.So it is important to understand the mechanism of spin relaxation and processes of spin transport.
In this thesis,we first give a brief review of Spintronics on the mechanism of spin relaxation,spin detection and spin generation.And then,we present our work on spin transport in(110)-oriented GaAs/AlGaAs quantum well(QW).Usually,the properties of spin transport is assumed to be the same as that of charge transport,but recent results demonstrate that spin diffusion constant D_s is reduced due to Coulomb interaction.So the properties of spin transport need to be exploited in detail experimentally.Transient spin grating(TSG) is a very important technique to determine D_s and characterize the processes of spin and charge transport.When two coherent beams of pulse laser with orthogonal linear(collinear) polarization interfere, the helicity(intensity) of light will be modulated periodically across the excitation spot.As a consequence,spatially-modulated spin(charge) density,which is so called transient spin(concentration) grating,will be generated in the sample according to the optical selection rules.In our system,the heterodyne scheme,which can provides 4-5 orders of magnitude of improvement in the signal,is used to detect the signal combining the lock-in technique.In addition,it is easy to convert the spin grating to concentration,create the different period of grating by a special configuration
We measure the spin lifetime in a single(110)-oriented GaAs/AlGaAs QW at room temperature(RT).Maximum of spin lifetime is about 1.22ns under low excitation power.We found that spin lifetime decreases with increasing excitation power.In an intrinsic(110)-oriented QW,spin lifetime is longer due to suppression of D'yakonov-Perel' mechanism of spin relaxation.The exchange interaction between hole and electron will result in the spin relaxation.Increasing hole concentration with high excitation power is the main reason of the decrease of spin lifetime.The signals of transient grating are measured by TSG at RT.Both signals of transient spin and concentration gratings are described by a mono-exponential decay.We found the decay rate of a fixed-period spin grating is accelerated by decreasing pump power. Power-dependence D_s presents a complex process:fast decrease-slow decrease-constant.We also measure the ambipolar D_c by transient concentration grating.D_c keeps in a constant and is independent on pump power.We contribute it to that D_c is determined by the diffusion processes of holes due to larger effective mass of hole comparing to that of electron.
Spintronics or spin-based electronics,which has been paid intense attentions in the field of Condensed Matter Physics and Information Sciences,aims to exploit the spin degree of freedom of the electron to develop a new generation of electronic devices.Two of the important issues on realizing the spintronics device are how to prolong the spin relaxation time and the spin diffusion length.So it is important to understand the mechanism of spin relaxation and processes of spin transport.
In this thesis,we first give a brief review of Spintronics on the mechanism of spin relaxation,spin detection and spin generation.And then,we present our work on spin transport in(110)-oriented GaAs/AlGaAs quantum well(QW).Usually,the properties of spin transport is assumed to be the same as that of charge transport,but recent results demonstrate that spin diffusion constant D_s is reduced due to Coulomb interaction.So the properties of spin transport need to be exploited in detail experimentally.Transient spin grating(TSG) is a very important technique to determine D_s and characterize the processes of spin and charge transport.When two coherent beams of pulse laser with orthogonal linear(collinear) polarization interfere, the helicity(intensity) of light will be modulated periodically across the excitation spot.As a consequence,spatially-modulated spin(charge) density,which is so called transient spin(concentration) grating,will be generated in the sample according to the optical selection rules.In our system,the heterodyne scheme,which can provides 4-5 orders of magnitude of improvement in the signal,is used to detect the signal combining the lock-in technique.In addition,it is easy to convert the spin grating to concentration,create the different period of grating by a special configuration
We measure the spin lifetime in a single(110)-oriented GaAs/AlGaAs QW at room temperature(RT).Maximum of spin lifetime is about 1.22ns under low excitation power.We found that spin lifetime decreases with increasing excitation power.In an intrinsic(110)-oriented QW,spin lifetime is longer due to suppression of D'yakonov-Perel' mechanism of spin relaxation.The exchange interaction between hole and electron will result in the spin relaxation.Increasing hole concentration with high excitation power is the main reason of the decrease of spin lifetime.The signals of transient grating are measured by TSG at RT.Both signals of transient spin and concentration gratings are described by a mono-exponential decay.We found the decay rate of a fixed-period spin grating is accelerated by decreasing pump power. Power-dependence D_s presents a complex process:fast decrease-slow decrease-constant.We also measure the ambipolar D_c by transient concentration grating.D_c keeps in a constant and is independent on pump power.We contribute it to that D_c is determined by the diffusion processes of holes due to larger effective mass of hole comparing to that of electron.
引文
[1]G E Moore.Cramming more components onto integrated circuits[J].Electronics.1965,38:8
[2]S.D.Sarma,Spintronics[J].American Scientist,2001,89:516
[3]D.Grundler,Spintronics[J].Physics World,2002 15:39-43
[4]S.A.Wolf el al.,Spintronics:A Spin-Based Electronics Vision for the Future [J].Science,2001,294:1488-1495
[5]D.D.Awschalom,M.E.Flatte,and N.Samarth.Spintronics[J].Scientific American 2002 286,66-69.
[6]M.N.Baibich,J.M.Broto,A.Fert,F.Nguyen Van Dau,F.Petroff el al.Giant Magnetoresistance of(001)Fe/(001)Cr Magnetic[J].Phys.Rev.Lett.1988 61,2472-2475
[7]J.BarnaS,A.Fuss,R.E.Camley,P.Grunberg,and W.Zinn.Novel magnetoresistance effect in layered magnetic structures Theory and experiment [J].Phys.Rev.B 1990,42,8110-8120.
[8]G.Prinz.Magnetoelectronics[J].Science 1998,282,1660-1663
[9]B.Dieny,V.S.Speriosu,S.S.P.Parkin,B.A.Gurney,D.R.Wilhoit,and D.Mauri.Giant magnetoresistance in soft ferromagnetic multilayers[J].Phys.Rev.B 1991 43,1297-1300
[10]R.von Helmolt,J.Wecker,B.Holzapfel,L.Schultz,and K.Samwer.Giant negative magetoresistance in perovskitelike La_2/3Ba_(1/3)MnO_x ferromagnetic films [J].Phys.Rev.Lett.1993 71,2331-2333.
[11]J.S.Moodera,Lisa R.Kinder,Terrilyn M.Wong,and P.Meservey.Large Magnetoresistance at Room Temperature in Ferromagnetic Thin Film Tunnel Junctions[J].Phys.Rev.Lett.1995,74,3273-3276.
[12]J.F.Gregg,I.Petej,E.Jouguelet and C.Dennis.Spin electronics-a review[J].J.Phys.D:Appl.Phys.2002,35,R121-125.
[13]I.utic,J.Fabian,and S.Das Sarma.Spintronics:Fundamentals and applications [J].Rev.Mod.Phys.2004,76,323-410.
[14]O.Madelung,Physics of Ⅲ-Ⅴ Compounds[M].Wilev:New York,1964.
[15]费浩生.非线性光学[M].北京:高等教育出版社.1990
[16]Peter Y.Yu and Manuel Cardona.Fundamentals of Semiconductors[M].Berlin:
Springer,2005.
[17]Poland Winkler.Spin-orbit coupling Effects in Two-Dimensional Electron and Hole Systems [M].Berlin:Springer,2003.
[18]G.Dresselhaus.Spin-Orbit Coupling Effects in Zinc Blende Structures [J].Phys.Rev.1955 100,580-586.
[19]Y.A.Bychkov and E.Rashba,Pis'ma Zh.Eksp.Teor.Fiz.Sov.Phys.JETP Lett 39,66(1984)
[20]M.I.D'yakonov and V.I.Perel,Zh.Eksp.Teor.Fiz [J].1971,60 Sov.Phys.JETP 38,10531.
[21]R.J.Elliott.Spin-Orbit Coupling in Band Theory-Character Tables for Some “Double”Space Groups [J].Phys.Res.1954,96,280-287.
[22]Y.Yafet.Calculation of the g Factor of Metallic Sodium [J].Phys.Res.1952,85,478-478.
[23]F.Meier and B.P.Zakharchenya.Optical Orientation [M].North-Holland:Amsterdam,1984.
[24]L.jiang,M.Q.Weng,M.W.Wu.and J.L.Cheng.Diffusion and transport of spin pulses in an n-type semiconductor quantum well [J].J.Appl.Phys.2005,98,113702.
[25]M.W.Wu.Kinetic Thory of Spin Coherence of Electrons in Semiconductors [J].J.Superconductivity,2001,14,245-259.
[26]M.Q.Weng,M.W.Wu.High temperature spin dephasing in n-typed GaAs quantum wells.[J].2003 Phys.Rev.B 68,075312.
[27]D.D.Awschalom,D.Loss,and N.Samarth Semiconductor Spintronics and Quantum Computation [M].Berlin:Springer,2002.
[28]D.D.Awschalom,M.Flatte.Challenges for semiconductor Spintronics[J].Nature Physics 2007,3 153-159.
[29]G.Schmidt,D.Ferrand,L.W.Molenkamp,A.T.Filip,and B.J.Van Wees.Fundamental obstacle for electrical spin injection from a ferromagnetic metal into a diffusive semiconductor [J].Phys.Rev.B 2000 63,R4790-R4793.
[30]S.F.Alvarado and P.Renaud.Observation of Spin polarized-electron tunneling from a ferromagnet into GaAs [J].Phys.Rev Lett 1992 68,1387-1390.
[31]V.P.Labella,D.W.Bullock,Z.Ding,el al.,Spatially resolved Spin-injection Probability for Gallium Arsenide [J].Science 2001 292,1518-1521.
[32]E.I.Rashba Theory of electrical spin injection:Tunnel contacts as a solution of the conductivity mismatch problem[J].Phys.Rev.B 2000,62,R16267-R16270.
[33]S.K.Upadhyay,Richard N.Louie,and R.A.Buhrman.Spin filtering by ultrathin ferromagnetic films[J].Appl.Phys.Lett,1999 74.3881-3883.
[34]R.Jansen,O.M.J.VantErve,S.D.Kim,R.Vlutters,P.S.Anil Kumar,and J.C.Lodder.The spin-valve transistor:Fabrication,and physics(invited)[J].J Appl Phys,2001,89:7431-7436.
[35]R.R.Parsons.Band-To-Band Optical Pumping in Solids and Polarized Photoluminescence[J].Phys.Rev.Lett.1969,23,1152-1154.
[36]X.Lou,C.Adelmann,M.Furis,S.A.Crooker,C.J.Palmstrm,and P.A.Crowell.Electrical Detection of Spin Accumulation at a Ferromagnet-Semiconductor Interface[J].Phys.Rev.Lett.2006,96,176603.
[37]Xiaohua.Lou,C.Adelmann,S.A.Crooker,E.S.Garlid el al.,Electrical detection of spin transport in lateral ferromagnet-semiconductor devices[J].Nature Phys.2007,3,197-202.
[38]Michael E.Flatte,Jeff M.Byers.Spin Diffusion in Semiconductors[J].Phys.Rev.Lett.2000,84,4220-4223.
[39]I.D Amico,and G.Vignale.Spin diffusion in doped semiconductors:The role of Coulomb interactions[J].Europhys.Lett.2001,55,566-572.
[40]C.P.Weber,N.Gedik,J.E.Moore,J.Orenstein,J,Stephens,D.D.Awschalom.Observation of spin Coulomb drag in a two-dimensional electron gas[J].Nature.2005,437,1330-1333.
[41]M.Q.Weng and M.W.Wu.Longitudinal spin decoherence in spin diffusion in semiconductors[J].Phys.Rev.B 2002,66,235109-235113.
[42]M.Q.Weng,M.W.Wu and Q.W.Shi.Spin oscillations in transient diffusion of a spin pulse in n-type semiconductor quantum wells[J].Phys.Rev.B 2004,69,125310-125314.
[43]Yuriy V.Pershin.Long-lived spin coherence states in semiconductor heterostructures[J].Phys.Rev.B 2005,71,155317-155322.
[44]S.A.Crooker and D.L.Smith.Imaging Spin Flows in Semiconductors Subject to Electric,Magnetic,and Strain Fields[J].Phys.Rev.Lett.2005,94,236601.
[45]黄昆,韩汝琦.固体物理学[M].北京:高等教育出版社.2002.
[46]A.R.Cameron.P.Riblet.and A.Miller.Spin,Grating and the Measurement of Electron Drift Mobility Multiple Quantum Well Semiconductors[M].Phys.Rev. Let t.1996,76 4793-4796.
[47]M.Q.Weng and M.W.Wu.Kinetic theory of spin transport in n-type semiconductor quantum wells[J].J.Appl.Phys 2003,93.410-420.
[48]H.J.Eichler,P.Giinter,and D.W.Pohl.Laser-Induced Dynamic Gratings[M].Berlin:Springer-Verlag.1986.
[49]Nuh Gedik and Joseph Orenstein.Absolute phase measurement in heterodyne detection of transient gratings[J].Optics Letter 2004,29 2109-2111.
[50]R.Winkler.con-mat/0605390
[51]D.H(a|¨)gele,M.Oestreich,W.M.R(u|¨)hle,N.Nestle,and K.Eberl.Spin transport in GaAs[J].Appl.Phys.Lett.1998,73,1580-1582.
[52]J.M.Kikkawa and D.D.Awschalom.Lateral drag of spin coherence in gallium arsenide[J].Nature 1999,397,139-141.
[53]N.Gedik,J.Orenstein,Ruixing Liang,D.A.Bonn,W.N.Hardy.Diffusion of Nonequilibrium Quasi-Particles in a Cuprate Superconductor[J].Science.2003,300,1410-1412.
[54]S.G.Carter,Z.Chen,and S.T.Cundiff.Optical Measurement and Control of Spin Diffusion in n-Doped GaAs Quantum Wells[J].Phys.Rev.Lett.2006,97,136602.
[55]C.P.Weberl,J.Orenstein,B.Andrei Bernevig Shou-Cheng Zhang,Jason Stephens and D.D.Awschalom.Nondiffusive Spin Dynamics in a Two-Dimensional Electron Gas[J].Phys.Rev.Lett.2007,98,076604.
[56]T.Lshiguro,Y.Toda,and S.Adachi Appl.Exciton spin relaxation in GaN observed by spin grating experiment[J].Appl.Phys.Lett.2007,90,011904.
[57]Baoli Liu,Hongming Zhao,Jia Wang,Linsheng Liu,Wenxin Wang,and Dongmin Chen.Electron density dependence of in-plane spin relaxation anisotropy in GaAs/A1GaAs two-dimensional electron gas[J].Appl.Phys.Lett.2007,90,112111.
[58]M.I.D'yakonov,and V.I.Perel.Spin relaxation of conduction electrons in noncentrosymmetric semiconductors[J].Soy.Phys.Solid State,1972,13,3023
[59]Y.Ohno,R.Terauchi,T.Adachi,F.Matsukura,and H.Ohno.Spin Relaxation in GaAs(110) Quantum Wells.[J].Phys.Rev.Lett.1999,83,4196-4199.
[60]I.D' Amico.G.Vignale.Spin Coulomb drag in the two-dimensional electron liquid.[J].Phys.Rev.B 2003 68 045307
[2]S.D.Sarma,Spintronics[J].American Scientist,2001,89:516
[3]D.Grundler,Spintronics[J].Physics World,2002 15:39-43
[4]S.A.Wolf el al.,Spintronics:A Spin-Based Electronics Vision for the Future [J].Science,2001,294:1488-1495
[5]D.D.Awschalom,M.E.Flatte,and N.Samarth.Spintronics[J].Scientific American 2002 286,66-69.
[6]M.N.Baibich,J.M.Broto,A.Fert,F.Nguyen Van Dau,F.Petroff el al.Giant Magnetoresistance of(001)Fe/(001)Cr Magnetic[J].Phys.Rev.Lett.1988 61,2472-2475
[7]J.BarnaS,A.Fuss,R.E.Camley,P.Grunberg,and W.Zinn.Novel magnetoresistance effect in layered magnetic structures Theory and experiment [J].Phys.Rev.B 1990,42,8110-8120.
[8]G.Prinz.Magnetoelectronics[J].Science 1998,282,1660-1663
[9]B.Dieny,V.S.Speriosu,S.S.P.Parkin,B.A.Gurney,D.R.Wilhoit,and D.Mauri.Giant magnetoresistance in soft ferromagnetic multilayers[J].Phys.Rev.B 1991 43,1297-1300
[10]R.von Helmolt,J.Wecker,B.Holzapfel,L.Schultz,and K.Samwer.Giant negative magetoresistance in perovskitelike La_2/3Ba_(1/3)MnO_x ferromagnetic films [J].Phys.Rev.Lett.1993 71,2331-2333.
[11]J.S.Moodera,Lisa R.Kinder,Terrilyn M.Wong,and P.Meservey.Large Magnetoresistance at Room Temperature in Ferromagnetic Thin Film Tunnel Junctions[J].Phys.Rev.Lett.1995,74,3273-3276.
[12]J.F.Gregg,I.Petej,E.Jouguelet and C.Dennis.Spin electronics-a review[J].J.Phys.D:Appl.Phys.2002,35,R121-125.
[13]I.utic,J.Fabian,and S.Das Sarma.Spintronics:Fundamentals and applications [J].Rev.Mod.Phys.2004,76,323-410.
[14]O.Madelung,Physics of Ⅲ-Ⅴ Compounds[M].Wilev:New York,1964.
[15]费浩生.非线性光学[M].北京:高等教育出版社.1990
[16]Peter Y.Yu and Manuel Cardona.Fundamentals of Semiconductors[M].Berlin:
Springer,2005.
[17]Poland Winkler.Spin-orbit coupling Effects in Two-Dimensional Electron and Hole Systems [M].Berlin:Springer,2003.
[18]G.Dresselhaus.Spin-Orbit Coupling Effects in Zinc Blende Structures [J].Phys.Rev.1955 100,580-586.
[19]Y.A.Bychkov and E.Rashba,Pis'ma Zh.Eksp.Teor.Fiz.Sov.Phys.JETP Lett 39,66(1984)
[20]M.I.D'yakonov and V.I.Perel,Zh.Eksp.Teor.Fiz [J].1971,60 Sov.Phys.JETP 38,10531.
[21]R.J.Elliott.Spin-Orbit Coupling in Band Theory-Character Tables for Some “Double”Space Groups [J].Phys.Res.1954,96,280-287.
[22]Y.Yafet.Calculation of the g Factor of Metallic Sodium [J].Phys.Res.1952,85,478-478.
[23]F.Meier and B.P.Zakharchenya.Optical Orientation [M].North-Holland:Amsterdam,1984.
[24]L.jiang,M.Q.Weng,M.W.Wu.and J.L.Cheng.Diffusion and transport of spin pulses in an n-type semiconductor quantum well [J].J.Appl.Phys.2005,98,113702.
[25]M.W.Wu.Kinetic Thory of Spin Coherence of Electrons in Semiconductors [J].J.Superconductivity,2001,14,245-259.
[26]M.Q.Weng,M.W.Wu.High temperature spin dephasing in n-typed GaAs quantum wells.[J].2003 Phys.Rev.B 68,075312.
[27]D.D.Awschalom,D.Loss,and N.Samarth Semiconductor Spintronics and Quantum Computation [M].Berlin:Springer,2002.
[28]D.D.Awschalom,M.Flatte.Challenges for semiconductor Spintronics[J].Nature Physics 2007,3 153-159.
[29]G.Schmidt,D.Ferrand,L.W.Molenkamp,A.T.Filip,and B.J.Van Wees.Fundamental obstacle for electrical spin injection from a ferromagnetic metal into a diffusive semiconductor [J].Phys.Rev.B 2000 63,R4790-R4793.
[30]S.F.Alvarado and P.Renaud.Observation of Spin polarized-electron tunneling from a ferromagnet into GaAs [J].Phys.Rev Lett 1992 68,1387-1390.
[31]V.P.Labella,D.W.Bullock,Z.Ding,el al.,Spatially resolved Spin-injection Probability for Gallium Arsenide [J].Science 2001 292,1518-1521.
[32]E.I.Rashba Theory of electrical spin injection:Tunnel contacts as a solution of the conductivity mismatch problem[J].Phys.Rev.B 2000,62,R16267-R16270.
[33]S.K.Upadhyay,Richard N.Louie,and R.A.Buhrman.Spin filtering by ultrathin ferromagnetic films[J].Appl.Phys.Lett,1999 74.3881-3883.
[34]R.Jansen,O.M.J.VantErve,S.D.Kim,R.Vlutters,P.S.Anil Kumar,and J.C.Lodder.The spin-valve transistor:Fabrication,and physics(invited)[J].J Appl Phys,2001,89:7431-7436.
[35]R.R.Parsons.Band-To-Band Optical Pumping in Solids and Polarized Photoluminescence[J].Phys.Rev.Lett.1969,23,1152-1154.
[36]X.Lou,C.Adelmann,M.Furis,S.A.Crooker,C.J.Palmstrm,and P.A.Crowell.Electrical Detection of Spin Accumulation at a Ferromagnet-Semiconductor Interface[J].Phys.Rev.Lett.2006,96,176603.
[37]Xiaohua.Lou,C.Adelmann,S.A.Crooker,E.S.Garlid el al.,Electrical detection of spin transport in lateral ferromagnet-semiconductor devices[J].Nature Phys.2007,3,197-202.
[38]Michael E.Flatte,Jeff M.Byers.Spin Diffusion in Semiconductors[J].Phys.Rev.Lett.2000,84,4220-4223.
[39]I.D Amico,and G.Vignale.Spin diffusion in doped semiconductors:The role of Coulomb interactions[J].Europhys.Lett.2001,55,566-572.
[40]C.P.Weber,N.Gedik,J.E.Moore,J.Orenstein,J,Stephens,D.D.Awschalom.Observation of spin Coulomb drag in a two-dimensional electron gas[J].Nature.2005,437,1330-1333.
[41]M.Q.Weng and M.W.Wu.Longitudinal spin decoherence in spin diffusion in semiconductors[J].Phys.Rev.B 2002,66,235109-235113.
[42]M.Q.Weng,M.W.Wu and Q.W.Shi.Spin oscillations in transient diffusion of a spin pulse in n-type semiconductor quantum wells[J].Phys.Rev.B 2004,69,125310-125314.
[43]Yuriy V.Pershin.Long-lived spin coherence states in semiconductor heterostructures[J].Phys.Rev.B 2005,71,155317-155322.
[44]S.A.Crooker and D.L.Smith.Imaging Spin Flows in Semiconductors Subject to Electric,Magnetic,and Strain Fields[J].Phys.Rev.Lett.2005,94,236601.
[45]黄昆,韩汝琦.固体物理学[M].北京:高等教育出版社.2002.
[46]A.R.Cameron.P.Riblet.and A.Miller.Spin,Grating and the Measurement of Electron Drift Mobility Multiple Quantum Well Semiconductors[M].Phys.Rev. Let t.1996,76 4793-4796.
[47]M.Q.Weng and M.W.Wu.Kinetic theory of spin transport in n-type semiconductor quantum wells[J].J.Appl.Phys 2003,93.410-420.
[48]H.J.Eichler,P.Giinter,and D.W.Pohl.Laser-Induced Dynamic Gratings[M].Berlin:Springer-Verlag.1986.
[49]Nuh Gedik and Joseph Orenstein.Absolute phase measurement in heterodyne detection of transient gratings[J].Optics Letter 2004,29 2109-2111.
[50]R.Winkler.con-mat/0605390
[51]D.H(a|¨)gele,M.Oestreich,W.M.R(u|¨)hle,N.Nestle,and K.Eberl.Spin transport in GaAs[J].Appl.Phys.Lett.1998,73,1580-1582.
[52]J.M.Kikkawa and D.D.Awschalom.Lateral drag of spin coherence in gallium arsenide[J].Nature 1999,397,139-141.
[53]N.Gedik,J.Orenstein,Ruixing Liang,D.A.Bonn,W.N.Hardy.Diffusion of Nonequilibrium Quasi-Particles in a Cuprate Superconductor[J].Science.2003,300,1410-1412.
[54]S.G.Carter,Z.Chen,and S.T.Cundiff.Optical Measurement and Control of Spin Diffusion in n-Doped GaAs Quantum Wells[J].Phys.Rev.Lett.2006,97,136602.
[55]C.P.Weberl,J.Orenstein,B.Andrei Bernevig Shou-Cheng Zhang,Jason Stephens and D.D.Awschalom.Nondiffusive Spin Dynamics in a Two-Dimensional Electron Gas[J].Phys.Rev.Lett.2007,98,076604.
[56]T.Lshiguro,Y.Toda,and S.Adachi Appl.Exciton spin relaxation in GaN observed by spin grating experiment[J].Appl.Phys.Lett.2007,90,011904.
[57]Baoli Liu,Hongming Zhao,Jia Wang,Linsheng Liu,Wenxin Wang,and Dongmin Chen.Electron density dependence of in-plane spin relaxation anisotropy in GaAs/A1GaAs two-dimensional electron gas[J].Appl.Phys.Lett.2007,90,112111.
[58]M.I.D'yakonov,and V.I.Perel.Spin relaxation of conduction electrons in noncentrosymmetric semiconductors[J].Soy.Phys.Solid State,1972,13,3023
[59]Y.Ohno,R.Terauchi,T.Adachi,F.Matsukura,and H.Ohno.Spin Relaxation in GaAs(110) Quantum Wells.[J].Phys.Rev.Lett.1999,83,4196-4199.
[60]I.D' Amico.G.Vignale.Spin Coulomb drag in the two-dimensional electron liquid.[J].Phys.Rev.B 2003 68 045307