A magnetic field-controlled spin-current diode is theoretically proposed,which consists of a junction with an interacting quantum dot sandwiched between a pair of nonmagnetic electrodes.By applying a spin bias VS acro...A magnetic field-controlled spin-current diode is theoretically proposed,which consists of a junction with an interacting quantum dot sandwiched between a pair of nonmagnetic electrodes.By applying a spin bias VS across the junction,a pure spin current can be obtained in a certain gate voltage regime,regardless of whether the Coulomb repulsion energy exists.More interestingly,if we applied an external magnetic field on the quantum dot,we observed a clear asymmetry in the spectrum of spin current IS as a function of spin bias,while the charge current always decays to zero in the Coulomb blockade regime.Such asymmetry in the current profile suggests a spin diode-like behavior with respect to the spin bias,while the net charge through the device is almost zero.Different from the traditional charge current diode,this design can change the polarity direction and rectifying ability by adjusting the external magnetic field,which is very convenient.This device scheme can be compatible with current technologies and has potential applications in spintronics or quantum processing.展开更多
We present a robust and computationally efficient image reconstruction and object detection algorithm suitable for a microwave holographic vision system with several microwave sensors and a single emission source to d...We present a robust and computationally efficient image reconstruction and object detection algorithm suitable for a microwave holographic vision system with several microwave sensors and a single emission source to detect the presence and the nature of road obstacles impeding driving in the near vehicle zone. The holographic visualization technique allows reconstructing the spatial microwave scattering density in non-optical setting, detecting by lattice of sensors both amplitude and phase of a reflected signal We discuss versions of an algorithm, determine and analyze its resolution limits for various distances with different number of sensors for a one-dimensional test problem of detecting two walls （or posts） separated by a gap at a fixed distance. The interval between sensors needed for a reliable reconstruction equals about one Fresnel zone width. We show that detection distances and spatial resolution achieved （better than 20 cm on distances up to 4.5 m） were sufficient for near-vehicle object detection purposes.展开更多
We investigate spin-dependent electron transport through graphene-based Rash ba-strain double junctions. It is found that when electrons are injected from left normal graphene region, high spin polarization oscillatio...We investigate spin-dependent electron transport through graphene-based Rash ba-strain double junctions. It is found that when electrons are injected from left normal graphene region, high spin polarization oscillation is achieved due to the wave-vector-dependent resonant tunneling. The spin polarization is negligible once the incident direction is reversed. Such a remarkable difference arises from pseudogap caused by the Rashba spin-orbit interaction.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant No.11404322)the Natural Science Foundation of Huai’an(Grant No.HAB202150).
文摘A magnetic field-controlled spin-current diode is theoretically proposed,which consists of a junction with an interacting quantum dot sandwiched between a pair of nonmagnetic electrodes.By applying a spin bias VS across the junction,a pure spin current can be obtained in a certain gate voltage regime,regardless of whether the Coulomb repulsion energy exists.More interestingly,if we applied an external magnetic field on the quantum dot,we observed a clear asymmetry in the spectrum of spin current IS as a function of spin bias,while the charge current always decays to zero in the Coulomb blockade regime.Such asymmetry in the current profile suggests a spin diode-like behavior with respect to the spin bias,while the net charge through the device is almost zero.Different from the traditional charge current diode,this design can change the polarity direction and rectifying ability by adjusting the external magnetic field,which is very convenient.This device scheme can be compatible with current technologies and has potential applications in spintronics or quantum processing.
基金Acknowledgments We gratefully acknowledge the support from the Russian Science Foundation, project number 16-19-00181, for this work.
文摘We present a robust and computationally efficient image reconstruction and object detection algorithm suitable for a microwave holographic vision system with several microwave sensors and a single emission source to detect the presence and the nature of road obstacles impeding driving in the near vehicle zone. The holographic visualization technique allows reconstructing the spatial microwave scattering density in non-optical setting, detecting by lattice of sensors both amplitude and phase of a reflected signal We discuss versions of an algorithm, determine and analyze its resolution limits for various distances with different number of sensors for a one-dimensional test problem of detecting two walls （or posts） separated by a gap at a fixed distance. The interval between sensors needed for a reliable reconstruction equals about one Fresnel zone width. We show that detection distances and spatial resolution achieved （better than 20 cm on distances up to 4.5 m） were sufficient for near-vehicle object detection purposes.
基金Supported by the National Natural Science Foundation of China under Grant Nos.11364019,11165008,11065007the Foundation of East China Jiaotong University under Grant No.09121038
文摘We investigate spin-dependent electron transport through graphene-based Rash ba-strain double junctions. It is found that when electrons are injected from left normal graphene region, high spin polarization oscillation is achieved due to the wave-vector-dependent resonant tunneling. The spin polarization is negligible once the incident direction is reversed. Such a remarkable difference arises from pseudogap caused by the Rashba spin-orbit interaction.
