Non-Hermitian physics of levitated nanoparticle array

TL;DR

This paper proposes using an array of levitated nanoparticles to explore non-Hermitian physics, revealing rich dynamical phases and unique spectral features through non-Bloch band theory analysis.

Contribution

It introduces a controlled platform of levitated nanoparticle arrays for studying non-Hermitian physics, including the analysis of non-Bloch bands and the discovery of novel dynamical phases.

Findings

Identification of rich dynamical phases including unstable and critical phases.

Discovery of a self-crossing point in the continuum band due to long-range interactions.

Analysis of non-Hermitian skin effect in the nanoparticle array.

Abstract

The ability to control levitated nanoparticles allows one to explore various fields of physics, including quantum optics, quantum metrology, and nonequilibrium physics. It has been recently demonstrated that the arrangement of two levitated nanoparticles naturally realizes the tunable nonreciprocal dipole-dipole interaction. Motivated by this development, we here propose and analyze an array of levitated nanoparticles as an ideal platform to study non-Hermitian physics in a highly controlled manner. We employ the non-Bloch band theory to determine the continuum bands of the proposed setup and investigate the non-Hermitian skin effect therein. In particular, we point out that the levitated nanoparticle array exhibits rich dynamical phases, including the dynamically unstable phase and the unconventional critical phase where the spectral singularity persists over a broad region of the controllable parameters. We also show that the long-range nature of the dipole-dipole interaction gives rise to the unique self-crossing point of the continuum band.