Tracking electron pathways with magnetic field: Aperiodic Aharonov-Bohm oscillations in coherent transport through a periodic array of quantum dots

TL;DR

This paper investigates how magnetic fields influence electron tunneling in a quantum dot array, revealing complex and aperiodic Aharonov-Bohm oscillations due to interference effects, with potential for pathway enumeration.

Contribution

It demonstrates the occurrence of aperiodic Aharonov-Bohm oscillations in a quantum dot array under magnetic fields and introduces a method to enumerate tunneling pathways.

Findings

Aharonov-Bohm oscillations are complex and aperiodic unless the magnetic field slope is rational.

Magnetic field sweeps at various tilt angles can enumerate individual tunneling pathways.

Interference of multiple pathways causes the complex oscillation patterns observed.

Abstract

We study resonant tunneling through a periodic square array of quantum dots sandwiched between modulation-doped quantum wells. If a magnetic field is applied parallel to the quantum dot plane, the tunneling current exhibits a highly complex Aharonov-Bohm oscillation pattern due to the interference of multiple pathways traversed by a tunneling electron. Individual pathways associated with conductance beats can be enumerated by sweeping the magnetic field at various tilt angles. Remarkably, Aharonov-Bohm oscillations are aperiodic unless the magnetic field slope relative to the quantum dot lattice axes is a rational number.