Full Counting Statistics Of Electron Transport In The Spin Blockade Regime Through A Double Quantum Dot

Based on the special structure of a double quantum dot system,double quantum dot system has been widely studied and applied in the fields of physics,chemistry and biology.In this article,based on the Lindblad-type particle-resolved quantum master equation,we investigate the full counting statistics of electron transport through the double quantum dot in the spin-blockade regime.Firstly,we calculated the former three cumulants dependence on the left-right quantum dot energy detuning for different coherent coupling strength in the absence of external magnetic field.We found that the average Fano factor and the average skewness show a local maximum with the change of the energy detuning and that they have a local minimum at the aligned energy level.Moreover,the energy detunings at which the local maxima appear are determined by the crossing positions between the coherent eigenstates and the triplets1 T or1T-.Further,we studied the former three cumulants dependence on the energy detuning for different external magnetic field.We found that there is a same conclusion for the average Fano factor and the average skewness dependences on the energy detuning and that the average current is reduced and the average Fano factor and the average skewness increase with increasing the external magnetic field for the parameters chosen.Secondly,we investigated the effects of the weak nuclear magnetic field,the strong nuclear magnetic field and the inelastic tunneling on the transport characteristics.Results show that in the case of weak random nuclear field,the average Fano factor and the average skewness show a local maximum with the change of the magnitude of the external field.In the case of strong random nuclear field,the average Fano factor and the average skewness present a nearly monotonic behavior with the magnitude of the external magnetic field.For a given nuclear field realization,the Fano factorand the skewness can provide abundant transport information.In addition,the average current increases with increasing the inelastic transition while the average Fano factor and skewness decrease for the strong random nuclear magnetic field.Finally,we studied the effect of the ratio of the right and left tunneling rates on transport characteristics.When the ratio is reduced,the average Fano factor and the average skewness have a larger variation range for different coherent coupling strength.