Enhanced spin-dependent thermopower in a double-quantum-dot sandwiched between two-dimensional electron gases  

作　　者：Feng Chi Zhen-Guo Fu Liming Liu Ping Zhang 迟锋;付振国;刘黎明;张平(School of Electronic and Information Engineering,University of Electronic Science and Technology of China,Zhongshan Institute,Zhongshan 528400,China;Institute of Applied Physics and Computational Mathematics,Beijing 100088,China)

机构地区：[1]School of Electronic and Information Engineering,University of Electronic Science and Technology of China,Zhongshan Institute,Zhongshan 528400,China [2]Institute of Applied Physics and Computational Mathematics,Beijing 100088,China

出　　处：《Chinese Physics B》2019年第10期523-530,共8页中国物理B（英文版）

基　　金：Project supported by the National Natural Science Foundation of China(Grant Nos.61274101,51362031,and 11675023);the Innovation Development Fund of China Academy of Engineering Physics(CAEP)(Grant No.ZYCX1921-02);the Presidential Foundation of CAEP(Grant No.YZ2015014);the Initial Project of University of Electronic Science and Technology of China,Zhongshan Institute(Grant No.415YKQ02);Science and Technology Bureau of Zhongshan,China(Grant Nos.417S26 and 180809162197886)

摘　　要：We study the spin-dependent thermopower in a double-quantum-dot(DQD) embedded between the left and right two-dimensional electron gases(2DEGs) in doped quantum wells under an in-plane magnetic field. When the separation between the DQD is smaller than the Fermi wavelength in the 2DEGs, the asymmetry in the dots' energy levels leads to pronounced quantum interference effects characterized by the Dicke line-shape of the conductance, which are sensitive to the properties of the 2DEGs. The magnitude of the thermopower, which denotes the generated voltage in response to an infinitesimal temperature difference between the two 2DEGs under vanishing charge current, will be obviously enhanced by the Dicke effect. The application of the in-plane magnetic field results in the polarization of the spin-up and spin-down conductances and thermopowers, and enables an efficient spin-filter device in addition to a tunable pure spin thermopower in the absence of its charge counterpart.We study the spin-dependent thermopower in a double-quantum-dot(DQD) embedded between the left and right two-dimensional electron gases(2DEGs) in doped quantum wells under an in-plane magnetic field. When the separation between the DQD is smaller than the Fermi wavelength in the 2DEGs, the asymmetry in the dots’ energy levels leads to pronounced quantum interference effects characterized by the Dicke line-shape of the conductance, which are sensitive to the properties of the 2DEGs. The magnitude of the thermopower, which denotes the generated voltage in response to an infinitesimal temperature difference between the two 2DEGs under vanishing charge current, will be obviously enhanced by the Dicke effect. The application of the in-plane magnetic field results in the polarization of the spin-up and spin-down conductances and thermopowers, and enables an efficient spin-filter device in addition to a tunable pure spin thermopower in the absence of its charge counterpart.

关 键 词：quantum DOT spin-dependent THERMOPOWER TWO-DIMENSIONAL ELECTRON GASES 

分 类 号：O4[理学—物理]