Fractional Quantum Zeno Effect Emerging from Non-Hermitian Physics

TL;DR

This paper predicts a quantum non-Hermitian phenomenon called the fractional quantum Zeno effect, where engineered dissipation suppresses emission and induces photon antibunching, revealing fundamentally non-Hermitian quantum behavior.

Contribution

It introduces the fractional quantum Zeno effect arising from non-Hermitian physics and demonstrates its implications for photon statistics in quantum optics.

Findings

Fractional dissipation scaling near band edges.

Suppression of spontaneous emission via engineered dissipation.

Photon antibunching due to non-Hermitian effects.

Abstract

Exploring non-Hermitian phenomenology is an exciting frontier of modern physics. However, the demonstration of a non-Hermitian phenomenon that is quantum in nature has remained elusive. Here, we predict quantum non-Hermitian phenomena: the fractional quantum Zeno (FQZ) effect and FQZ-induced photon antibunching. We consider a quantum optics platform with reservoir engineering, where nonlinear emitters are coupled to a bath of decaying bosonic modes whose own decay rates form band structures. By engineering the dissipation band, the spontaneous emission of emitters can be suppressed by strong dissipation through an algebraic scaling with fractional exponents - the FQZ effect. This fractional scaling originates uniquely from the divergent dissipative density of states near the dissipation band edge, different from the traditional closed-bath context. We find FQZ-induced strong photon antibunching in the steady state of a driven emitter even for weak nonlinearities. Remarkably, we identify that the sub-Poissonian quantum statistics of photons, which has no classical analogs, stems here from the key role of non-Hermiticity. Our setup is experimentally feasible with the techniques used to design lattice models with dissipative couplings.