We propose a four-terminal device consisting of two parallel quantum dots with Rashba spin-orbit interaction （RSOI）, coupled to two side superconductor leads and two common ferromagnetic leads, respectively. The two...We propose a four-terminal device consisting of two parallel quantum dots with Rashba spin-orbit interaction （RSOI）, coupled to two side superconductor leads and two common ferromagnetic leads, respectively. The two ferromagnetic leads and two quantum dots form a ring threaded by Aharonov-Bohm （AB） flux. This device possesses normal quasiparticle transmission between the two ferromagnetic leads, and normal and crossed Andreev reflections providing conductive holes. For the appropriate spin polarization of the ferromagnetic leads, RSOI and AB flux, the pure spin-up （or spin-down） current without net charge current in the right lead, which is due to the equal numbers of electrons and holes with the same spin-polarization moving along the same direction, can be obtained by adjusting the gate voltage, which may be used in practice as a pure spin-current injector.展开更多
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
The effect of electropulse on the solidification structure of commercially pure aluminium was studied. The orthogonal array L9 was used to determine the effect of three process parameters of electropulse modification ...The effect of electropulse on the solidification structure of commercially pure aluminium was studied. The orthogonal array L9 was used to determine the effect of three process parameters of electropulse modification （EPM）, which were pulse current intensity, pulse frequency, and treating time. For each factor, three levels were chosen to cover the experimental region. According to the experimental results, the solidification structure of commercially pure aluminium was modified from large grains with columnar crystals to finer grains with equiaxed crystals, by allowing the electropulse to act on liquid aluminium. However, the solidification structures could be refined differently at different EPM parameters. Certain EPM parameters should be selected to get the optimum solidification structure. Among the three parameters, pulse frequency was the most important factor influencing the solidification structure, the secondary factor was current intensity, and treating time was the third one. The optimum parameters were the pulse frequency of 5 Hz, the current intensity of 68 A, and the treating time of l0 s.展开更多
Spintronics is a new discipline focusing on the research and application of electronic spin properties. After the discovery of the giant magnetoresistance effect in 1988, spintronics has had a huge impact on scientifi...Spintronics is a new discipline focusing on the research and application of electronic spin properties. After the discovery of the giant magnetoresistance effect in 1988, spintronics has had a huge impact on scientific progress and related applications in the development of information technology. In recent decades, the main motivation in spintronics has been efficiently controlling local magnetization using electron flow or voltage rather than controlling the electron flow using magnetization. Using spin-orbit coupling in a material can convert a charge current into a pure spin current(a flow of spin momenta without a charge flow) and generate a spin-orbit torque on the adjacent ferromagnets. The ability of spintronic devices to utilize spin-orbit torques to manipulate the magnetization has resulted in large-scale developments such as magnetic random-access memories and has boosted the spintronic research area. Here in, we review the theoretical and experimental results that have established this subfield of spintronics. We introduce the concept of a pure spin current and spin-orbit torques within the experimental framework, and we review transport-, magnetization-dynamics-, and opticalbased measurements and link then to both phenomenological and microscopic theories of the effect. The focus is on the related progress reported from Chinese universities and institutes, and we specifically highlight the contributions made by Chinese researchers.展开更多
A high-energy pulse power source applied for studying solidifieation of metals and a Rogowski coil for measuring strong pulse current were developed according to the requirement of the present experiment. The variatio...A high-energy pulse power source applied for studying solidifieation of metals and a Rogowski coil for measuring strong pulse current were developed according to the requirement of the present experiment. The variation of electrical current during the discharge of pulse power source was analyzed. Furthermore, the quantitative relation between peak current, pulse width and pulse frequency etc. versus voltage, capacitance and transmission line of discharging circuit was examined.展开更多
基金supported by the National Natural Science Foundation of China (Grant Nos. 10775091,10774094,10974124,and 11047172)the Excellent Youth and Midlife Scientist Scientific Research Encouragement Foundation of Shandong Province,China(Grant No. BS2010DS006)the Doctor Research Startup Foundation of Linyi University,China (Grant No. BS201023)
文摘We propose a four-terminal device consisting of two parallel quantum dots with Rashba spin-orbit interaction （RSOI）, coupled to two side superconductor leads and two common ferromagnetic leads, respectively. The two ferromagnetic leads and two quantum dots form a ring threaded by Aharonov-Bohm （AB） flux. This device possesses normal quasiparticle transmission between the two ferromagnetic leads, and normal and crossed Andreev reflections providing conductive holes. For the appropriate spin polarization of the ferromagnetic leads, RSOI and AB flux, the pure spin-up （or spin-down） current without net charge current in the right lead, which is due to the equal numbers of electrons and holes with the same spin-polarization moving along the same direction, can be obtained by adjusting the gate voltage, which may be used in practice as a pure spin-current injector.
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the National Natural Science Foundation of China (No.30160186).
文摘The effect of electropulse on the solidification structure of commercially pure aluminium was studied. The orthogonal array L9 was used to determine the effect of three process parameters of electropulse modification （EPM）, which were pulse current intensity, pulse frequency, and treating time. For each factor, three levels were chosen to cover the experimental region. According to the experimental results, the solidification structure of commercially pure aluminium was modified from large grains with columnar crystals to finer grains with equiaxed crystals, by allowing the electropulse to act on liquid aluminium. However, the solidification structures could be refined differently at different EPM parameters. Certain EPM parameters should be selected to get the optimum solidification structure. Among the three parameters, pulse frequency was the most important factor influencing the solidification structure, the secondary factor was current intensity, and treating time was the third one. The optimum parameters were the pulse frequency of 5 Hz, the current intensity of 68 A, and the treating time of l0 s.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11674142,51771099,11429401,and 51471081)the Program for Changjiang Scholars and Innovative Research Team in University,China(Grant No.IRT-16R35)
文摘Spintronics is a new discipline focusing on the research and application of electronic spin properties. After the discovery of the giant magnetoresistance effect in 1988, spintronics has had a huge impact on scientific progress and related applications in the development of information technology. In recent decades, the main motivation in spintronics has been efficiently controlling local magnetization using electron flow or voltage rather than controlling the electron flow using magnetization. Using spin-orbit coupling in a material can convert a charge current into a pure spin current(a flow of spin momenta without a charge flow) and generate a spin-orbit torque on the adjacent ferromagnets. The ability of spintronic devices to utilize spin-orbit torques to manipulate the magnetization has resulted in large-scale developments such as magnetic random-access memories and has boosted the spintronic research area. Here in, we review the theoretical and experimental results that have established this subfield of spintronics. We introduce the concept of a pure spin current and spin-orbit torques within the experimental framework, and we review transport-, magnetization-dynamics-, and opticalbased measurements and link then to both phenomenological and microscopic theories of the effect. The focus is on the related progress reported from Chinese universities and institutes, and we specifically highlight the contributions made by Chinese researchers.
文摘A high-energy pulse power source applied for studying solidifieation of metals and a Rogowski coil for measuring strong pulse current were developed according to the requirement of the present experiment. The variation of electrical current during the discharge of pulse power source was analyzed. Furthermore, the quantitative relation between peak current, pulse width and pulse frequency etc. versus voltage, capacitance and transmission line of discharging circuit was examined.
