摘要
We explore inelastic cotunneling through a strongly Coulomb-blockaded quantum dot attached to twoferromagnetic leads in the weak coupling limit using a generic quantum Langevin equation approach.We first developa B1och-type equation microscopically to describe the cotunneling-induced spin relaxation dynamics,and then developexplicit analytical expressions for the local magnetization,current,and its fluctuations.On this basis,we predict a novelzero-bias anomaly of the differential conductance in the absence of a magnetic field for the anti-parallel configuration,and asymmetric peak splitting in a magnetic field.Also,for the same system with large polarization,we find a negativezero-frequency differential shot noise in the low positive bias-voltage region. All these effects are ascribed to rapidspin-reversal due to underlying spin-flip cotunneling.
We explore inelastic cotunneling through a strongly Coulomb-blockaded quantum dot attached to two ferromagnetic leads in the weak coupling limit using a generic quantum Langevin equation approach.We first develop a B1och-type equation microscopically to describe the cotunneling-induced spin relaxation dynamics,and then develop explicit analytical expressions for the local magnetization,current,and its fluctuations.On this basis,we predict a novel zero-bias anomaly of the differential conductance in the absence of a magnetic field for the anti-parallel configuration, and asymmetric peak splitting in a magnetic field.Also,for the same system with large polarization,we find a negative zero-frequency differential shot noise in the low positive bias-voltage region. All these effects are ascribed to rapid spin-reversal due to underlying spin-flip cotunneling.
基金
The project supported by National Natural Science Foundation of China
the Shanghai Municipal Commission of Science and Technology
the Shanghai Pujiang Program
the Program for New Century Excellent Talents in Universities (NCET)
NJMH is supported by the DURINT program administered by the US Army Research Office, DAAD Grant No. 19-O1-1-0592
