Kondo resonance assisted thermoelectric transport through strongly correlated quantum dots  

作　　者：YongXi Cheng ZhenHua Li JianHua Wei HongGang Luo HaiQing Lin YiJing Yan 

机构地区：[1]Beijing Computational Science Research Center,Beijing 100193,China [2]Department of Science,Taiyuan Institute of Technology,Taiyuan 030008,China [3]School of Physical Science and Technology,Key Laboratory for Magnetism and Magnetic Materials of the MoE,Lanzhou University,Lanzhou 730000,China [4]Department of Physics,Renmin University of China,Beijing 100872,China [5]Hefei National Laboratory for Physical Sciences at the Microscale,University of Science and Technology of China,Hefei 230026,China

出　　处：《Science China(Physics,Mechanics & Astronomy)》2020年第9期118-126,共9页中国科学：物理学、力学、天文学（英文版）

基　　金：the National Natural Science Foundation of China(Grant Nos.11804245,11747098,11504017,11774418,11674139,11834005,21633006,and U1930402);the China Postdoctoral Science Foundation(Grant No.2019M660431);the Program for the Innovative Talents of Taiyuan Institute of Technology。

摘　　要：We theoretically studied the thermoelectric transport properties of a strongly correlated quantum dot system in the presence of the Kondo effect based on accurate numerical evaluations using the hierarchical equations of motion approach.The thermocurrent versus gate voltage shows a distinct sawtooth line-shape at high temperatures.In particular,the current changes from positive(hole charge)to negative(particle charge)in the electron number N=1 region due to the Coulomb blockade effect.However,at low temperatures,where the Kondo effect occurs,the thermocurrent’s charge polarity reverses,along with a significantly enhanced magnitude.As anticipated,the current sign can be analyzed by the occupation difference between particle and hole.Moreover,the characteristic turnover temperature can be further defined at which the influences of the Coulomb blockade and Kondo resonance are in an effective balance.Remarkably,the identified characteristic turnover temperature,as a function of the Coulomb interaction and dot-lead coupling,possessed a much higher value than the Kondo temperature.When a magnetic field is applied,a spin-polarized thermocurrent can be obtained,which could be tested in future experiments.

关 键 词：thermoelectric transport strongly correlated quantum dot Kondo resonance spin-polarized thermocurrent 

分 类 号：O469[理学—凝聚态物理]