Energy-band echoes: Time-reversed light emission from optically driven quasiparticle wavepackets

TL;DR

This paper introduces a novel energy-band echo phenomenon in quantum many-body systems, enabling time-reversed light emission from quasiparticle wavepackets driven by optical pulses, applicable across various insulators and dimensions.

Contribution

It demonstrates that quasiparticle wavepackets can be reversed by electric-field pulses, revealing a new optical echo effect linked to energy-band structures in complex quantum systems.

Findings

Echoes occur in band and correlated insulators.

Echo frequency reflects quasiparticle dispersion relations.

Applicable in one- and higher-dimensional systems.

Abstract

The at-will control of quantum states is a primary goal of quantum science and technology. The celebrated Hahn echo exemplifies such quantum-state control based on a time-reversal process in a few-level system. Here, we propose a different echo phenomenon associated with the energy-band structure in quantum many-body systems. We show that the dynamics of quasiparticle wavepackets can be reversed by a driving electric-field pulse, yielding echoes with the time-reversed waveform of the optical excitation pulse when the quasiparticles recombine. The present echoes are observed not only in band insulators but also in correlated insulators, including a Mott insulator and a spontaneously-broken-symmetry charge-ordered insulator, in one- and higher-dimensional systems, irrespective of the integrability of the models. Analytical expressions reveal the conditions under which the echoes appear, and they also indicate that the frequency of the echo pulses reflects the dispersion relation for quasiparticles such as electron-hole pairs, doublon-holon pairs, and kink-antikink pairs. These findings provide a framework for all-optical momentum-resolved spectroscopy of the quasiparticles in quantum many-body systems.