Preprint · October 2025
Momentum-resolved two-dimensional spectroscopy as a probe of nonlinear quantum field dynamics
Preprint, arXiv:2509.25147 (2025)
Abstract
Emergent collective excitations constitute a hallmark of interacting quantum many-body systems, yet in solid-state platforms their study has been largely limited by the constraints of linear-response probes and by finite momentum resolution. We propose to overcome these limitations by combining the spatial resolution of ultracold atomic systems with the nonlinear probing capabilities of two-dimensional spectroscopy (2DS). As a concrete illustration, we analyze momentum-resolved 2DS of the quantum sine-Gordon model describing the low energy dynamics of two weakly coupled one-dimensional Bose-Einstein condensates. This approach reveals distinctive many-body signatures, most notably asymmetric cross-peaks reflecting the interplay between isolated (B2 breather) and continuum (B1 pair) modes. The protocol further enables direct characterization of anharmonicity and disorder, establishing momentum-resolved 2DS as both a powerful diagnostic for quantum simulators and a versatile probe of correlated quantum matter.
Cite
@misc{desantis2025momentumresolvedtwodimensionalspectroscopyprobe,
archiveprefix = {arXiv},
author = {Duilio De Santis and Alex Gómez Salvador and Nataliia Bazhan and Sebastian Erne and Maximilian Prüfer and Claudio Guarcello and Davide Valenti and Jörg Schmiedmayer and Eugene Demler},
eprint = {2509.25147},
month = {oct},
primaryclass = {cond-mat.quant-gas},
title = {Momentum-resolved two-dimensional spectroscopy as a probe of nonlinear quantum field dynamics},
url = {https://arxiv.org/abs/2509.25147},
year = {2025}
}