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

Abstract

In nanostructures, the light-matter interaction can be engineered to be chiral. In the fully quantum regime, 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. Furthermore, the directional photon-exchange between many emitters in a chiral system may enable the creation of highly exotic quantum states. Here, we present a new way of implementing chiral quantum optics $-$ we use a low-noise quantum dot in an open microcavity. Specifically, 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, and is optimised $\text{in situ}$ by tuning the photon-emitter coupling to the optimal operating condition ($\beta =0.5$). Proof that the non-reciprocity arises from a single quantum emitter lies in the nonlinearity with increasing input laser power, and 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. The results pave the way to a single-photon phase shifter, and, by exploiting a quantum dot spin, to two-photon gates and quantum non-demolition single-photon detectors.

References in corpus (8)

• Chiral Quantum Optics
• Nanophotonic quantum phase switch with a single atom
• All-Optical Routing of Single Photons by a One-Atom Switch Controlled by a Single Photon
• Theory of single-photon transport in a single-mode waveguide coupled to a cavity containing a two-level atom
• Quantum optical circulator controlled by a single chirally coupled atom
• Giant Optical Non-linearity induced by a Single Two-Level System interacting with a Cavity in the Purcell Regime
• Single-molecule vacuum Rabi splitting: four-wave mixing and optical switching at the single-photon level
• Efimov States of Strongly Interacting Photons

Cited by in corpus (6)

• Chiral quantum optics: recent developments, and future directions
• Realisation of a Coherent and Efficient One-Dimensional Atom
• Nonunitary Gate Operations by Dissipation Engineering
• Non-Hermitian unidirectional routing of photonic qubits
• Steady-state entanglement of spin qubits mediated by nonreciprocal and chiral magnons
• Dissipation-assisted few-photon optical diode