Room Temperature Quantum Coherent Revival in an Ensemble of Artificial Atoms

TL;DR

This paper demonstrates quantum coherence revival at room temperature in an ensemble of quantum dots, highlighting potential for practical quantum information processing components.

Contribution

It reports the first observation of quantum coherence revival in quantum dots at room temperature, with detailed analysis of decoherence mechanisms.

Findings

Quantum coherence revival observed at room temperature.

Homogeneous linewidth extracted via double-pulse and photon echo techniques.

Decoherence mainly due to carrier-carrier and carrier-phonon interactions.

Abstract

We report a demonstration of the hallmark concept of quantum optics: periodic collapse and revival of quantum coherence (QCR) in a room temperature ensemble of quantum dots (QD). Control over quantum states, inherent to QCR, together with the dynamical QD properties present an opportunity for practical room temperature building blocks of quantum information processing. The amplitude decay of QCR is dictated by the QD homogeneous linewidth, thus, enabling its extraction in a double-pulse Ramsey-type experiment. The more common photon echo technique was also invoked and yielded the same linewidth. Measured electrical bias and temperature dependencies of the transverse relaxation times enable to determine the two main decoherence mechanisms: carrier-carrier and carrier-phonon scatterings.