We theoretically investigate the wave-vector filtering(WVF)effect for electrons in an antiparallel asymmetric doubleδ-magnetic-barrier microstructure under a bias,which can be fabricated experimentally by patterning ...We theoretically investigate the wave-vector filtering(WVF)effect for electrons in an antiparallel asymmetric doubleδ-magnetic-barrier microstructure under a bias,which can be fabricated experimentally by patterning two asymmetric ferromagnetic(FM)stripes on the top and the bottom of GaAs/AlxGa1−xAs heterostructure,respectively.It is found that an appreciable WVF effect appears because of an essentially two-dimensional(2D)process for electrons across this microstructure.WVF effect is found to be sensitive to the applied bias.WVF efficiency can be tuned by changing bias,which may lead to an electrically-controllable momentum filter for nanoelectronics device applications.展开更多
To some extent,the operational quickness of semiconductor devices depends on the transmission time of an electron through semiconductor nanostructures.However,the calculation of transmission time is very difficult,tha...To some extent,the operational quickness of semiconductor devices depends on the transmission time of an electron through semiconductor nanostructures.However,the calculation of transmission time is very difficult,thanks to both the contentious definition of the transmission time in quantum mechanics and the complicated effective potential functions experienced by electrons in semiconductor devices.Here,based on an improved transfer matrix method to numerically solve the Schr?dinger equation and H G Winful’s relationship to calculate the dwell time,we develop a numerical approach to evaluate the transmission time of an electron in semiconductor devices.Compared to the exactly resolvable case of the rectangular potential barrier,the established numerical approach possesses high precision and small error,which may be employed to explore the dynamic response and operating speed of semiconductor devices.This proposed numerical method is successfully applied to the calculation of dwell time for an electron in double rectangular potential barriers and the dependence of transmission time on the number of potential barriers is revealed.展开更多
We theoretically explore the manipulation of a temporal electron-spin splitter by aδ-potential in an embedded magnetic-elec tric-barrier micro structure(EMEBM),which is constructed by patterning a ferromagnetic strip...We theoretically explore the manipulation of a temporal electron-spin splitter by aδ-potential in an embedded magnetic-elec tric-barrier micro structure(EMEBM),which is constructed by patterning a ferromagnetic stripe and a Schottky-metal stripe on the top and bottom of an InAs/Al_(x)In_(1-x)As heterostructure,respectively.Spin polarization of the dwell time remains,even though aδ-potential is inserted by atomic-layer doping.Both the magnitude and sign of the spinpolarized dwell time can be manipulated by changing the weight or position of the 6-potential.Thus,a structurally controllable temporal electron-spin splitter can be obtained for spintronics device applications.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.11864009).
文摘We theoretically investigate the wave-vector filtering(WVF)effect for electrons in an antiparallel asymmetric doubleδ-magnetic-barrier microstructure under a bias,which can be fabricated experimentally by patterning two asymmetric ferromagnetic(FM)stripes on the top and the bottom of GaAs/AlxGa1−xAs heterostructure,respectively.It is found that an appreciable WVF effect appears because of an essentially two-dimensional(2D)process for electrons across this microstructure.WVF effect is found to be sensitive to the applied bias.WVF efficiency can be tuned by changing bias,which may lead to an electrically-controllable momentum filter for nanoelectronics device applications.
基金supported jointly by the National Natural Science Foundation of China(11864009 and 62164005)the Guangxi Natural Science Foundation of China(2021JJB110053)
文摘To some extent,the operational quickness of semiconductor devices depends on the transmission time of an electron through semiconductor nanostructures.However,the calculation of transmission time is very difficult,thanks to both the contentious definition of the transmission time in quantum mechanics and the complicated effective potential functions experienced by electrons in semiconductor devices.Here,based on an improved transfer matrix method to numerically solve the Schr?dinger equation and H G Winful’s relationship to calculate the dwell time,we develop a numerical approach to evaluate the transmission time of an electron in semiconductor devices.Compared to the exactly resolvable case of the rectangular potential barrier,the established numerical approach possesses high precision and small error,which may be employed to explore the dynamic response and operating speed of semiconductor devices.This proposed numerical method is successfully applied to the calculation of dwell time for an electron in double rectangular potential barriers and the dependence of transmission time on the number of potential barriers is revealed.
基金supported by the Science and Technology Innovation Plan Project of Hunan Province in China(S2019JJQNJJ2177)the National Natural Science Foundation of China(11864009)。
文摘We theoretically explore the manipulation of a temporal electron-spin splitter by aδ-potential in an embedded magnetic-elec tric-barrier micro structure(EMEBM),which is constructed by patterning a ferromagnetic stripe and a Schottky-metal stripe on the top and bottom of an InAs/Al_(x)In_(1-x)As heterostructure,respectively.Spin polarization of the dwell time remains,even though aδ-potential is inserted by atomic-layer doping.Both the magnitude and sign of the spinpolarized dwell time can be manipulated by changing the weight or position of the 6-potential.Thus,a structurally controllable temporal electron-spin splitter can be obtained for spintronics device applications.
