Year: 2026
Type: article
Abstract: Critical quantum field theories occupy a central position in modern theoretical physics for their inherent universality stemming from long-range correlations. As an example, the Tomonaga-Luttinger liquid (TLL) describes a wealth of one-dimensional quantum systems at low temperatures. Its behavior is deeply rooted in the emergence of an effective Fermi sea, leading to power-law correlations and Friedel oscillations. A promising direction to realize systems exhibiting novel universal behavior beyond TLL is through the generalization of the underlying Fermi sea. In this Letter, we show that fractional Fermi seas with reduced occupancy arise in an integrable Bose gas driven out of equilibrium by cyclic changes in interactions across the full range of repulsive and attractive regimes. The correlation functions feature signatures of criticality incompatible with a conventional TLL, suggesting a novel critical phase. Our predictions, based on generalized hydrodynamics, are directly relevant to cold atoms.
Source: Physical Review Letters
DOI: 10.1103/j3s5-gjpf
Language: English
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
Funders: Deutsche Forschungsgemeinschaft, National Natural Science Foundation of China, Österreichischen Akademie der Wissenschaften, Austrian Science Fund, Ministerio de Ciencia e Innovación, Österreichische Forschungsförderungsgesellschaft, National Science and Technology Major Project, European Research Council, Agencia Estatal de Investigación
OpenAlex ID: W7164004052