Coherently driven non-classical light emission from a quantum dot

TL;DR

This paper demonstrates the first resonant and coherent excitation of a quantum dot, enabling non-classical light emission with improved photon properties crucial for quantum information applications.

Contribution

It introduces a novel method for coherently exciting quantum dots, overcoming limitations of incoherent pumping and enhancing quantum control capabilities.

Findings

Observation of oscillatory photon statistics at high driving fields

First demonstration of resonant coherent excitation of a quantum dot

Enhanced quantum control for single-photon emission

Abstract

Narrow line-widths and the possibility of enhanced spontaneous emission via coupling to microcavities make semiconductor quantum dots ideal for harnessing coherent quantum phenomena at the single photon level. So far, however, all approaches have relied on incoherent pumping, which limits the desirable properties of the emission. In contrast, coherent excitation was recognized to be necessary for providing both improved photon indistinguishability and high efficiency, and offers the quantum control capabilities required for basic qubit manipulations. Here we achieve, for the first time, resonant and coherent excitation of a quantum dot with simultaneous collection of the non-classical photon emission. Second-order correlation measurements show the unique signature of a coherently-driven two-level quantum emitter: the photon statistics become oscillatory at high driving fields, reflecting the coherent evolution of the excitonic ground state of the quantum dot.