A chiral one-dimensional atom using a quantum dot in an open microcavity

Antoniadis, N.O. and Tomm, N. and Jakubczyk, T. and Schott, R. and Valentin, S.R. and Wieck, A.D. and Ludwig, A. and Warburton, R.J. and Javadi, A.

Volume: 8 Pages:
DOI: 10.1038/s41534-022-00545-z
Published: 2022

In a chiral one-dimensional atom, a photon propagating in one direction interacts with the atom; a photon propagating in the other direction does not. Chiral quantum optics has applications in creating nanoscopic single-photon routers, circulators, phase-shifters, and two-photon gates. Here, we implement chiral quantum optics using a low-noise quantum dot in an open microcavity. We demonstrate the non-reciprocal absorption of single photons, a single-photon diode. The non-reciprocity, the ratio of the transmission in the forward-direction to the transmission in the reverse direction, is as high as 10.7 dB. This is achieved by tuning the photon-emitter coupling in situ to the optimal operating condition (β = 0.5). Proof that the non-reciprocity arises from a single quantum emitter lies in the photon statistics—ultralow-power laser light propagating in the diode’s reverse direction results in a highly bunched output (g(2)(0) = 101), showing that the single-photon component is largely removed. © 2022, The Author(s).

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