Aharonov-Bohm Oscillations Changed by Indirect Interdot Tunneling via Electrodes in Parallel-Coupled Vertical Double Quantum Dots

TL;DR

This study investigates how indirect interdot coupling via electrodes influences Aharonov-Bohm oscillations in a parallel-coupled vertical double quantum dot, revealing period halving and phase shifts explained by a detailed calculation.

Contribution

It demonstrates the impact of indirect interdot tunneling via electrodes on AB oscillations, providing a new understanding of quantum interference effects in double quantum dots.

Findings

AB oscillation period halves with negative gate voltage

Phase shifts by half a period observed in antibonding state

Calculation confirms the role of indirect interdot coupling via electrodes

Abstract

Aharonov-Bohm (AB) oscillations are studied for a parallel coupled vertical double quantum dot with a common source and drain electrode. We observe AB oscillations of current via a one-electron bonding state as the ground state and an anti-bonding state as the excited state. As the center gate voltage becomes more negative, the oscillation period is clearly halved for both the bonding and antibonding states, and the phase changes by half a period for the antibonding state. This result can be explained by a calculation that takes account of the indirect interdot coupling via the two electrodes.