Exact quantum scars from kinetic frustration for cross-platform realizations

TL;DR

This paper introduces exact quantum scars created through kinetic frustration, demonstrating their realization in various quantum platforms and proposing methods to predict and optimize their lifetimes.

Contribution

The authors develop a simple, exact model of quantum scars from kinetic frustration, applicable across multiple quantum simulation platforms, and introduce a heuristic for optimizing scar lifetimes.

Findings

Frustrated hardcore bosons exhibit tunable persistent oscillations.

A scar within a non-integrable Fermi-Hubbard model is proposed.

A heuristic for predicting and optimizing scar lifetimes is introduced.

Abstract

Quantum many-body scars are nonthermal states exhibiting persistent revivals in an otherwise ergodic, nonintegrable quantum system. Here we leverage the phenomenon of kinetic frustration -- the destructive interference of multiple quantum paths -- to create exact scars. The simplicity makes these models directly suitable for implementation on multiple existing quantum simulation platforms. In particular, we show how frustrated hardcore bosons in cold atom Bose-Hubbard simulators and polar molecule or Rydberg atom tweezer arrays have persistent oscillations whose lifetimes can be tuned with experimentally accessible parameters, like the Hubbard interaction or a Floquet drive. Second, we propose an experimentally realizable scar within a non-integrable Fermi-Hubbard model where the frustration arises from the fermionic exchange statistics, which admits a one-to-one mapping with the bosonic model in the scar subspace. Finally, we introduce a practical heuristic based on the energy distribution of eigenstates for systematically predicting and optimizing quantum many-body scar lifetimes. Their cross-platform realizability and long lifetimes make them well-suited for benchmarking coherence and exploring nonergodic dynamics in current and near-term quantum devices.