Counterflow leads to roton spectra in locally interacting superfluids

Fuente: arXiv
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Main Authors: Alperin, Samuel, Timmermans, Eddy
Format: Preprint
Published: 2025
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author Alperin, Samuel
Timmermans, Eddy
author_facet Alperin, Samuel
Timmermans, Eddy
contents The dynamics of strongly interacting quantum fluids such as Helium II are fundamentally distinct from those of dilute, contact-interacting atomic Bose-Einstein condensates. Most dramatically, superfluids with finite-range interactions can support excitations with a roton-like dispersion, exhibiting a minimum at finite wavenumber. Here we introduce a mechanism through which roton spectra can emerge in superfluids without any nonlocal interactions, instead resulting from the collective excitations of two counterflowing, zero-range interacting condensates. As our mechanism relies only on the nonlinear dynamics of classical fields, this work opens the door to the realization of roton dynamics in the broad class of physical systems governed by coupled nonlinear-Schrödinger equations.
format Preprint
id arxiv_https___arxiv_org_abs_2507_08985
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Counterflow leads to roton spectra in locally interacting superfluids
Alperin, Samuel
Timmermans, Eddy
Quantum Gases
Pattern Formation and Solitons
The dynamics of strongly interacting quantum fluids such as Helium II are fundamentally distinct from those of dilute, contact-interacting atomic Bose-Einstein condensates. Most dramatically, superfluids with finite-range interactions can support excitations with a roton-like dispersion, exhibiting a minimum at finite wavenumber. Here we introduce a mechanism through which roton spectra can emerge in superfluids without any nonlocal interactions, instead resulting from the collective excitations of two counterflowing, zero-range interacting condensates. As our mechanism relies only on the nonlinear dynamics of classical fields, this work opens the door to the realization of roton dynamics in the broad class of physical systems governed by coupled nonlinear-Schrödinger equations.
title Counterflow leads to roton spectra in locally interacting superfluids
topic Quantum Gases
Pattern Formation and Solitons
url https://arxiv.org/abs/2507.08985