Coherent coupling of individual quantum dots measured with phase-referenced two-dimensional spectroscopy: Photon echo versus double quantum coherence

Valentin Delmonte,Christian Schneider,Gilles Nogues,Jacek Kasprzak,Tomasz Jakubczyk,Wolfgang Langbein,Judith F Specht,Marten Richter,Martin Kamp,Sven Höfling

doi:10.1103/physrevb.96.041124

Abstract

We employ two-dimensional (2D) coherent, nonlinear spectroscopy to investigate couplings within individual InAs quantum dots (QD) and QD molecules. Swapping pulse ordering in a two-beam sequence permits to distinguish between rephasing and non-rephasing four-wave mixing (FWM) configurations. We emphasize the non-rephasing case, allowing to monitor two-photon coherence dynamics. Respective Fourier transform yields a double quantum 2D FWM map, which is corroborated with its single quantum counterpart, originating from the rephasing sequence. We introduce referencing of the FWM phase with the one carried by the driving pulses, overcoming the necessity of its active-stabilization, as required in 2D spectroscopy. Combining single and double quantum 2D FWM, provides a pertinent tool in detecting and ascertaining coherent coupling mechanisms between individual quantum systems, as exemplified experimentally.

Highlights

Nuclear magnetic resonance (NMR) spectroscopy conceived phase-locked, multipulse techniques, yielding multidimensional spectra by Fourier transforming temporal sequences into respective frequency coordinates [1,2]
We introduce referencing of the four-wave mixing (FWM) phase with the one carried by the driving pulses, overcoming the necessity of its active stabilization, as required in 2D spectroscopy
We point out two advancements with respect to our recent reports [16,20]: First, we demonstrate 2D FWM constructed from two-photon coherences—known as double quantum 2D FWM [21,22,23,24]—driven on individual transitions, quantum dots (QDs) exciton-biexciton systems (GXB) [25]

Summary

Introduction

Nuclear magnetic resonance (NMR) spectroscopy conceived phase-locked, multipulse techniques, yielding multidimensional spectra by Fourier transforming temporal sequences into respective frequency coordinates [1,2]. Combining single and double quantum 2D FWM provides a pertinent tool in detecting and ascertaining coherent coupling mechanisms between individual quantum systems, as exemplified experimentally.

Results

Conclusion