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arXiv · 2105.05774

Quench Spectroscopy of a Disordered Quantum System

L. Villa·S. J. Thomson·L. Sanchez-Palencia
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Abstract

The characterization of excitations in disordered quantum systems is a central issue in connection with glass physics and many-body localization. Here, we show that quench spectroscopy of a disordered model, as realized from its out-of-equilibrium dynamics following a global quench, allows us to fully characterize the spectral properties of the disordered phases. In the Bose-Hubbard model, a clear signature of gapless excitations in momentum-resolved spectroscopy enables us to accurately locate the Mott insulator to Bose glass transition, while the presence or absence of a well-defined soundlike mode distinguishes the superfluid from the Bose glass phase. Moreover, spatially-resolved spectroscopy provides local spectral properties and allows us to extract the typical spacing of gapless regions, giving a second independent way to uniquely identify all three phases. Our findings have far-ranging implications for a variety of experimental platforms, and offer a powerful and versatile probe of the low-energy phases of disordered systems.

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BibTeXRIS

L. Villa, S. J. Thomson, L. Sanchez-Palencia. 2021-05-12. Quench Spectroscopy of a Disordered Quantum System. https://doi.org/10.1103/physreva.104.l021301

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