Room Temperature Quantum Coherent Revival in an Ensemble of Artificial Atoms

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.