Spin－filtering effect in a double－quantum－dot structure subjected to thermal bias
ZHANG Hairui
Abstract：Spin－polarized current in a serially connected double quantum dot coupled to two metal leads is studied. Under an oscillating magnetic field, the coupling strength between the two dots becomes spin－depend-ent, which can affect not only the magnitude but also the peaks′ positions of the current. In the absence of the intradot Coulomb interaction, with increasing spin asymmetry of the interdot coupling strength, the spin－up cur-rent develops double－peak structure, whereas the spin－down one remains single－peak configuration with re-duced current strength. As a result of it, the spin polarization of the current becomes larger, an idea condition for filtering electron spin. Such a phenomenon will emerge under small temperature difference between the two leads, and can be used for designing sensitive and lower energy consumption thermspin devices. The Coulomb interaction in the dots will further split the currents′peaks and enables the emerge of peak in one spin component current whereas that of the other spin direction remains a minimum value. By adjusting the sign of the spin－de-pendent interdot coupling strength, the spin direction of the transported current can be adjusted accordingly.
Keywords：quantum dotsspin－filteringthermospin
Publication Date：2019-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：6( 135-140 )