Subharmonic fidelity revival in a driven PXP model

TL;DR

This paper investigates how periodic driving can control quantum fidelity revivals in the PXP model, revealing mechanisms behind subharmonic responses and enhancing understanding of quantum many-body scars.

Contribution

It provides a systematic analysis of driving conditions that enhance or alter fidelity revivals in the PXP model, linking quantum scarring to free spin-1/2 models.

Findings

Periodic driving can enhance fidelity revival magnitude.

Driving parameters can change revival frequencies.

Quantum fidelity in PXP is explained by free spin-1/2 model.

Abstract

The PXP model hosts a special set of nonergodic states, referred to as quantum many-body scars. One of the consequences of quantum scarring is the periodic revival of the wave function fidelity. It has been reported that quantum fidelity revival occurs in the PXP model for certain product states, and periodic driving of chemical potential can enhance the magnitude of quantum revival, and can even change the frequencies of revival showing the subharmonic response. Although the effect of the periodic driving in the PXP model has been studied in the limit of certain perturbative regimes, the general mechanism of such enhanced revival and frequency change has been barely studied. In this work, we investigate how periodic driving in the PXP model can systematically control the fidelity revival. Particularly, focusing on the product state so called a Neel state, we analyze the condition of driving to enhance the magnitude of revival or change the frequencies of revival. To clarify the reason of such control, we consider the similarities between the PXP model and the free spin-1/2 model in graph theoretical analysis, and show that the quantum fidelity feature in the PXP model is well explained by the free spin-1/2 model. In addition, under certain limit of the driving parameters, analytic approach to explain the main features of the fidelity revival is also performed. Our results give an insight of the scarring nature of the periodically driven PXP model and pave the way to understand their (sub-)harmonic responses and controls.