Bias-induced chiral current and geometrical blockade in triangular triple quantum dot

¹ Department of Physics, Renmin University of China - Beijing 100872, China
² School of Electronic, Electrical and Communication Engineering, University of Chinese Academy of Sciences Beijing 100049, China
³ Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China Hefei, Anhui 230026, China

^(a) wjh@ruc.edu.cn

Received: 24 January 2020
Accepted: 8 April 2020

Abstract

We theoretically investigate the quantum transport properties of a triangular triple quantum dot (TTQD) ring connected to two reservoirs by an analytical derivation and an accurate hierarchical equations-of-motion calculation. We initially demonstrate a bias-induced chiral current under zero magnetic field caused by the coupling between the spin gauge field and spin current in a nonequilibrium TTQD that induces a scalar spin chirality, which lifts the chiral degeneracy and the time inversion symmetry. The chiral current oscillates with the bias within the Coulomb blockade regime, suggesting that the chiral spin qubit can be controlled by purely electrical manipulations. Then, the geometrical blockade of the transport current due to the localization of chiral states is elucidated by spectral function analysis.