The influence of electron-phonon interactions on third-harmonic generation in a square quantum well is investigated. The first- and third-harmonic generation coefficient is obtained by using compact-density-matrix app...The influence of electron-phonon interactions on third-harmonic generation in a square quantum well is investigated. The first- and third-harmonic generation coefficient is obtained by using compact-density-matrix approach and iterative method, and the numerical results are presented for a GaAs square quantum well. The results show that the third-harmonic generation coefficient is obviously enhanced after considering the influence of electron-phonon interactions.展开更多
Based on superconducting quantum interference devices （SQUIDs） coupled to a cavity, we propose a scheme for implementing a quantum controlled-phase gate （QPG） and Deutsch-Jozsa （D J） algorithm by a controllable ...Based on superconducting quantum interference devices （SQUIDs） coupled to a cavity, we propose a scheme for implementing a quantum controlled-phase gate （QPG） and Deutsch-Jozsa （D J） algorithm by a controllable interaction. In the present scheme, the SQUID works in the charge regime, and the cavity field is ultilized as quantum data-bus, which is sequentially coupled to only one qubit at a time. The interaction between the selected qubit and the data bus, such as resonant and dispersive interaction, can be realized by turning the gate capacitance of each SQUID. Especially, the bus is not excited and thus the cavity decay is suppressed during the implementation of DJ algorithm. For the QPG operation, the mode of the bus is unchanged in the end of the operation, although its mode is really excited during the operations. Finally, for typical experiment data, we analyze simply the experimental feasibility of the proposed scheme. Based on the simple operation, our scheme may be realized in this solid-state system, and our idea may be realized in other systems.展开更多
By applying the slave boson technique, we have studied the electron transport through double-dotAharonov-Bohm interferometer in the Kondo regime. For the system with symmetric quantum dots, the linear con-ductance is ...By applying the slave boson technique, we have studied the electron transport through double-dotAharonov-Bohm interferometer in the Kondo regime. For the system with symmetric quantum dots, the linear con-ductance is shown to be enhanced by Kondo effect, but it is suppressed in the deep dot level regime in the presence ofnonzero magnetic flux. The Aharonov Bohm oscillations of the conductance are also investigated.展开更多
Three electrodeposited Fe-Ni,Fe-Co,and Fe-Ni-Co cores of thin film transformer are prepared on silicon(100) substrates,which are sputtered a 90 nm thick film of Cu acting as the seed layer.The core films consisting of...Three electrodeposited Fe-Ni,Fe-Co,and Fe-Ni-Co cores of thin film transformer are prepared on silicon(100) substrates,which are sputtered a 90 nm thick film of Cu acting as the seed layer.The core films consisting of Fe-Ni 20:80,Fe-Co 60:40 and Fe-Ni-Co 10:60:30,respectively,are deposited using direct current electrodeposition.The surface texture,electrical and magnetic properties are surveyed by scanning electron microscopy(SEM),superconducting quantum interference device(SQUID),etc.The wave transmission ability and efficiency of thin film transformer with these cores,inputting the sine wave,are compared.All the analyses indicate that FeNi alloy films display the optimal magnetic properties and excellent transformer performance.展开更多
We theoretically present the results for a scanning tunneling transport between a metallic tip and a Kondo lattice.We calculate the density of states(DOS)and the tunneling current and differential conductance(DC)under...We theoretically present the results for a scanning tunneling transport between a metallic tip and a Kondo lattice.We calculate the density of states(DOS)and the tunneling current and differential conductance(DC)under different conduction-fermion band hybridization and temperature in the Kondo lattice.It is found that the hybridization strength and temperature give asymmetric coherent peaks in the DOS separated by the Fermi energy.The corresponding current and DC intensity depend on the temperature and quantum interference effect among the c-electron and f-electron states in the Kondo lattice.展开更多
基金The project supported by National Natural Science Foundation of China under Grant No. 60478010, the Science and Technology Committee of Guangdong Province of China under Grant Nos. 2004B10301014 and 04105406, Science and Technology Bureau of Guangzhou under Grant Nos. 200J1-C0031 and 2004J1-C0226, and Education Bureau of Guangzhou under Grant No. 2024
文摘The influence of electron-phonon interactions on third-harmonic generation in a square quantum well is investigated. The first- and third-harmonic generation coefficient is obtained by using compact-density-matrix approach and iterative method, and the numerical results are presented for a GaAs square quantum well. The results show that the third-harmonic generation coefficient is obviously enhanced after considering the influence of electron-phonon interactions.
基金The project supported by the Natural Science Foundation of Hunan Province under Grant No. 06jj50014, Key Project Foundation of the Education Commission of Hunan Province under Grant No. 06A055 and National Natural Science Foundation of China under Grant No. 10574126
文摘Based on superconducting quantum interference devices （SQUIDs） coupled to a cavity, we propose a scheme for implementing a quantum controlled-phase gate （QPG） and Deutsch-Jozsa （D J） algorithm by a controllable interaction. In the present scheme, the SQUID works in the charge regime, and the cavity field is ultilized as quantum data-bus, which is sequentially coupled to only one qubit at a time. The interaction between the selected qubit and the data bus, such as resonant and dispersive interaction, can be realized by turning the gate capacitance of each SQUID. Especially, the bus is not excited and thus the cavity decay is suppressed during the implementation of DJ algorithm. For the QPG operation, the mode of the bus is unchanged in the end of the operation, although its mode is really excited during the operations. Finally, for typical experiment data, we analyze simply the experimental feasibility of the proposed scheme. Based on the simple operation, our scheme may be realized in this solid-state system, and our idea may be realized in other systems.
基金The project supported by National Natural Science Foundation of China under Grant No.19975031
文摘By applying the slave boson technique, we have studied the electron transport through double-dotAharonov-Bohm interferometer in the Kondo regime. For the system with symmetric quantum dots, the linear con-ductance is shown to be enhanced by Kondo effect, but it is suppressed in the deep dot level regime in the presence ofnonzero magnetic flux. The Aharonov Bohm oscillations of the conductance are also investigated.
基金supported by the National Natural Science Foundation of China (Grant No. 60874101)
文摘Three electrodeposited Fe-Ni,Fe-Co,and Fe-Ni-Co cores of thin film transformer are prepared on silicon(100) substrates,which are sputtered a 90 nm thick film of Cu acting as the seed layer.The core films consisting of Fe-Ni 20:80,Fe-Co 60:40 and Fe-Ni-Co 10:60:30,respectively,are deposited using direct current electrodeposition.The surface texture,electrical and magnetic properties are surveyed by scanning electron microscopy(SEM),superconducting quantum interference device(SQUID),etc.The wave transmission ability and efficiency of thin film transformer with these cores,inputting the sine wave,are compared.All the analyses indicate that FeNi alloy films display the optimal magnetic properties and excellent transformer performance.
基金Supported by the National Natural Science Foundation of China under Grant No.11547203the Research Project of Education Department in Sichuan Province of China under Grant No.15ZB0457
文摘We theoretically present the results for a scanning tunneling transport between a metallic tip and a Kondo lattice.We calculate the density of states(DOS)and the tunneling current and differential conductance(DC)under different conduction-fermion band hybridization and temperature in the Kondo lattice.It is found that the hybridization strength and temperature give asymmetric coherent peaks in the DOS separated by the Fermi energy.The corresponding current and DC intensity depend on the temperature and quantum interference effect among the c-electron and f-electron states in the Kondo lattice.
