Nonreciprocal unconventional photon blockade in a spinning optomechanical system

Abstract

We propose how to achieve quantum nonreciprocity via unconventional photon blockade (UPB) in a compound device consisting of an optical harmonic resonator and a spinning optomechanical resonator. We show that, even with a very weak single-photon nonlinearity, nonreciprocal UPB can emerge in this system, i.e., strong photon antibunching can emerge only by driving the device from one side, but not from the other side. This nonreciprocity results from the Fizeau drag, leading to different splitting of the resonance frequencies for the optical counter-circulating modes. Such quantum nonreciprocal devices can be particularly useful in achieving back-action-free quantum sensing or chiral photonic communications. * miran@amu.edu.pl † jinghui73@gmail.com light, which is optimally sub-Poissonian in second order, g 2 (0) ≈ 0, and is generated in a weakly-nonlinear system allowing for multi-path interference (e.g., two linearlycoupled cavities, when one of them is also weakly coupled to a two-level atom). Thus, PB and UPB are induced by different effects: PB due to a large system nonlinearity and UPB via multi-path interference assuming even an extremely-weak system nonlinearity. Note that light generated via UPB can exhibit higher-order super-Poissonian photon-number statistics, g (n) (0) > 1 for some n > 2. Thus, UPB is, in general, not a good source of single photons. This short comparison of PB and UPB indicates that the term UPB, as coined in Ref.[39] and now commonly accepted, is fundamentally different from PB, concerning their physical mechanisms and properties of their generated light.Here, we propose to achieve and control nonreciprocal UPB with spinning devices. Nonreciprocal devices allow for the flow of light from one side but block it from the other. Thus, such devices can be applied in noisefree quantum information signal processing and quantum communication for cancelling interfering signals [40]. Nonreciprocal optical devices have been realized in OM devices [40][41][42], Kerr resonators [43][44][45], thermo systems [46][47][48], devices with temporal modulation [49,50], and non-Hermitian systems [51][52][53]. In a very recent experiment [54], 99.6% optical isolation in a spinning resonator has been achieved based on the optical Sagnac effect. However, these studies have mainly focused on the classical regimes; that is, unidirectional control of transmission rates instead of quantum noises. We also note that in recent works, single-photon diodes [55][56][57], unidirectional quantum amplifiers [58][59][60][61][62], and one-way quantum routers [63] have been explored. In particular, nonreciprocal PB was predicted in a Kerr resonator [64] or a quadratic OM system [65], which, however, relies on the conventional condition of strong single-photon nonlinearity. These quantum nonreciprocal devices have potential applications for quantum control of light in chiral and topological quantum technologies [66].

Dynamical blockade in a bosonic Josephson junction using optimal coupling

“…Closely related is the understanding of this interference phenomenon in terms of homodyning the signal [11], an idea which has been successfully used recently [12,13], see also the review [14]. Several variations have been suggested in order to improve unconventional photon blockade [15][16][17][18][19][20][21][22][23][24], while other blockade schemes based on similar ideas have been proposed [25][26][27][28][29][30][31][32]. Recently, the unconventional photon blockade was implemented experimentally [33,34].…”

Two-photon blockade and photon-induced tunneling generated by squeezing

“…Single-PB has been generalized to include two-PB and multi-PB effects [52][53][54][55][56][57][58][59]. Two-PB was first experimentally demonstrated by Hamsen et al in 2017 [44].…”

Nonreciprocity via Nonlinearity and Synthetic Magnetism

“…Such quantum nonreciprocal effect for transport photons with asymmetric statistical properties under exchange of source and detector is called nonreciprocal photon blockade, which is predicted firstly in a spinning Kerr resonator [21] based on the Fizeau light-dragging effect [22][23][24][25]. Nonreciprocal photon blockades were also predicted in multi-mode optomechanical systems based on directional nonlinear interaction [26] or quantum interference [27]. Nonreciprocal photon blockade may have important applications in the development of quantum nonreciprocal devices, which are crucial elements in chiral quantum technologies or topological photonics.…”