Weak-localization effect in the presence of magnetic impurities is studied in disordered two-dimensional tight-binding square lattices around half filling. Both the magnetic and nonmagnetic impurities are assumed to b...Weak-localization effect in the presence of magnetic impurities is studied in disordered two-dimensional tight-binding square lattices around half filling. Both the magnetic and nonmagnetic impurities are assumed to be randomly distributed on small fractions of the sites, while the nonmagnetic impurities have a strong potential yielding a unitary-limit scattering. We derive in details the expressions of diffusive π modes in the retarded-retarded (or advancedadvanced) channel, which result from the existence of particle-hole symmetry. The quantum interference correction to the density of states is calculated. While the magnetic-impurity scattering suppresses the quantum correction from π-mode cooperon, it does not affect the contribution of π-mode diffuson.展开更多
The extrinsic mechanism for anomalous Hall effect in ferromagnets is extended to include the contributionsboth from spin-orbit-dependent impurity scattering and from the spin-orbit coupling induced by external electri...The extrinsic mechanism for anomalous Hall effect in ferromagnets is extended to include the contributionsboth from spin-orbit-dependent impurity scattering and from the spin-orbit coupling induced by external electric fields.The results obtained suggest that, within the framework of the extrinsic mechanisms, the anomalous Hall current in aferromagnet may also contain a substantial amount of dissipationless contribution independent of impurity scattering.After the contribution from the spin-orbit coupling induced by external electric fields is included, the total anomalousHall conductivity is about two times larger than that due to spin-orbit dependent impurity scatterings.展开更多
Based on the Kubo formalism,the anomalous Hall effect in a magnetic two-dimensional hole gas withcubic-Rashba spin-orbit coupling is studied in the presence of 5-function scattering potential.When the weak,short-range...Based on the Kubo formalism,the anomalous Hall effect in a magnetic two-dimensional hole gas withcubic-Rashba spin-orbit coupling is studied in the presence of 5-function scattering potential.When the weak,short-rangeddisorder scattering is considered in the Born approximation,we find that the self-energy becomes diagonal inthe helicity basis and its value is independent of the wave number,and the vertex correction to the anomalous Hallconductivity due to impurity scattering vanishes when both subbands are occupied.That is to say,the anomalous Halleffect is not vanishing or influenced by the vertex correction for two-dimensional heavy-hole system,which is in sharpcontrast to the case of linear-Rashba spin-orbit coupling in the electron band when the short-range disorder scattering isconsidered and the extrinsic mechanism as well as the effect of external electric field on the SO interaction are ignored.展开更多
基金the Program for New Century Excellent Talents in Universities of China，中国科学院资助项目
文摘Weak-localization effect in the presence of magnetic impurities is studied in disordered two-dimensional tight-binding square lattices around half filling. Both the magnetic and nonmagnetic impurities are assumed to be randomly distributed on small fractions of the sites, while the nonmagnetic impurities have a strong potential yielding a unitary-limit scattering. We derive in details the expressions of diffusive π modes in the retarded-retarded (or advancedadvanced) channel, which result from the existence of particle-hole symmetry. The quantum interference correction to the density of states is calculated. While the magnetic-impurity scattering suppresses the quantum correction from π-mode cooperon, it does not affect the contribution of π-mode diffuson.
基金Supported by the National Natural Science Foundation of China under Grant No.10874049the State Key Program for Basic Research of China under Grant No.2007CB925204the Natural Science Foundation of Guangdong Province under Grant No.07005834
文摘The extrinsic mechanism for anomalous Hall effect in ferromagnets is extended to include the contributionsboth from spin-orbit-dependent impurity scattering and from the spin-orbit coupling induced by external electric fields.The results obtained suggest that, within the framework of the extrinsic mechanisms, the anomalous Hall current in aferromagnet may also contain a substantial amount of dissipationless contribution independent of impurity scattering.After the contribution from the spin-orbit coupling induced by external electric fields is included, the total anomalousHall conductivity is about two times larger than that due to spin-orbit dependent impurity scatterings.
基金Supported by the Research Fund for Outstanding Young Teachers in Higher Education Institutions of Shanghai under Grant No.gjd08040the Scientific Research Startup Funds of SUESthe National Natural Science Foundation of China under Grant No.C-6201-10-001
文摘Based on the Kubo formalism,the anomalous Hall effect in a magnetic two-dimensional hole gas withcubic-Rashba spin-orbit coupling is studied in the presence of 5-function scattering potential.When the weak,short-rangeddisorder scattering is considered in the Born approximation,we find that the self-energy becomes diagonal inthe helicity basis and its value is independent of the wave number,and the vertex correction to the anomalous Hallconductivity due to impurity scattering vanishes when both subbands are occupied.That is to say,the anomalous Halleffect is not vanishing or influenced by the vertex correction for two-dimensional heavy-hole system,which is in sharpcontrast to the case of linear-Rashba spin-orbit coupling in the electron band when the short-range disorder scattering isconsidered and the extrinsic mechanism as well as the effect of external electric field on the SO interaction are ignored.
