Chiral Quantum Optics and Optical Nonreciprocity Based on Susceptibility‐Momentum Locking

Abstract

The progress in chiral light–matter interaction in the quantum regime leads to emergence of chiral quantum optics and quantum nonreciprocity. Spin‐momentum locking is at the heart of chiral quantum optics. In this short review, the basic knowledge of optical nonreciprocity and susceptibility‐momentum locking (SML) is introduced as a novel mechanism for conducting chiral quantum optics. Various approaches achieving optical nonreciprocity based on SML are also reviewed. A perspective regarding the challenges in this direction will also be provided.

Reversible Optical Isolators and Quasi-Circulators Using a Magneto-Optical Fabry–Pérot Cavity

“…Dynamically reversing the propagation direction of light in NRODs is highly desirable, particularly for reconfigurable quantum networks. [2,[15][16][17][18][19][20][21][22][23][24][25] To circumvent the severe constraints imposed by strong magnetic fields, one effort is devoted to magnetfree optical nonreciprocity, including chiral quantum optics systems, [5,19,[26][27][28][29][30][31] spatiotemporal modulation of the medium, [32][33][34] optical nonlinearity, [3,[35][36][37][38][39][40][41][42] the Doppler effect, [20,[43][44][45][46][47] optomechanical resonators, [48][49][50][51][52] spinning resonators, [53] etc. An alternative avenue involves enhancing the MO effect by exploiting strong MO materials, [54][55]…”

Dynamic Nonreciprocity with a Kerr Nonlinear Resonator

“…[26][27][28][29][30][31][32][33][34] Susceptibility-momentum locking has become a new toolkit for realizing quantum nonreciprocity. [35] By using the macroscopic Doppler shift in a unidirectional moving atomic lattice, all-optical isolators and unidirectional reflectionless have been studied. [36][37][38] Alternatively, spinning resonators [39][40][41] and optomechanical resonators [42][43][44][45][46][47] are also used to achieve optical nonreciprocity, in particular, magnetic-free optical isolation.…”