Excitonic Aharonov-Bohm Effect in Isotopically Pure 70Ge/Si Type-II Quantum Dots

TL;DR

This study demonstrates the excitonic Aharonov-Bohm effect in isotopically pure 70Ge/Si quantum dots through magneto-photoluminescence, providing experimental evidence of phase coherence in localized electron wave functions.

Contribution

First experimental observation of the excitonic Aharonov-Bohm effect in isotopically pure Ge/Si quantum dots showing phase coherence of electron wave functions.

Findings

Oscillatory behavior in emission energy and intensity due to Aharonov-Bohm effect

Change in exciton ground state angular momentum with magnetic flux

Evidence of phase coherence in localized electron wave functions

Abstract

We report on a magneto-photoluminescence study of isotopically pure 70Ge/Si self-assembled type-II quantum dots. Oscillatory behaviors attributed to the Aharonov-Bohm effect are simultaneously observed for the emission energy and intensity of excitons subject to an increasing magnetic field. When the magnetic flux penetrates through the ring-like trajectory of an electron moving around each quantum dot, the ground state of an exciton experiences a change in its angular momentum. Our results provide the experimental evidence for the phase coherence of a localized electron wave function in group-IV Ge/Si self-assembled quantum structures.