Spin selective Aharonov-Bohm oscillations in a lateral triple quantum dot

TL;DR

This paper develops a theoretical model showing that in a triple quantum dot system, Aharonov-Bohm oscillations depend on electron spin states, enabling magnetic field control of spin-dependent electron transport.

Contribution

The study introduces a spin-sensitive theoretical framework for AB oscillations in triple quantum dots, highlighting spin singlet states as key to flux-dependent current modulation.

Findings

AB oscillations occur only for spin singlet states

Current depends on flux and spin orientation

Magnetic field can tune the spin valve effect

Abstract

We present a theory for spin selective Aharonov-Bohm oscillations in a lateral triple quantum dot. We show that to understand the Aharonov-Bohm (AB) effect in an interacting electron system within a triple quantum dot molecule (TQD) where the dots lie in a ring configuration requires one to not only consider electron charge but also spin. Using a Hubbard model supported by microscopic calculations we show that, by localizing a single electron spin in one of the dots, the current through the TQD molecule depends not only on the flux but also on the relative orientation of the spin of the incoming and localized electrons. AB oscillations are predicted only for the spin singlet electron complex resulting in a magnetic field tunable "spin valve".