Excited-State Phase Diagram of a Ferromagnetic Quantum Gas

authored by: Bernd Meyer-Hoppe, Fabian Anders, Polina Feldmann, Luis Santos, Carsten Klempt
Abstract: The ground-state phases of a quantum many-body system are characterized by an order parameter, which changes abruptly at quantum phase transitions when an external control parameter is varied. Interestingly, these concepts may be extended to excited states, for which it is possible to define equivalent excited-state quantum phase transitions. However, the experimental mapping of a phase diagram of excited quantum states has not yet been demonstrated. Here we present the experimental determination of the excited-state phase diagram of an atomic ferromagnetic quantum gas, where, crucially, the excitation energy is one of the control parameters. The obtained phase diagram exemplifies how the extensive Hilbert state of quantum many-body systems can be structured by the measurement of well-defined order parameters.
Organisation(s): Quantum Atom Optics
Institute of Theoretical Physics
Institute of Quantum Optics
QuantumFrontiers
CRC 1227 Designed Quantum States of Matter (DQ-mat)
External Organisation(s): University of British Columbia
Type: Article
Journal: Physical Review Letters
Volume: 131
ISSN: 0031-9007
Publication date: 12.2023
Publication status: Published
Peer reviewed: Yes
ASJC Scopus subject areas: Physics and Astronomy(all)
Electronic version(s): https://doi.org/10.48550/arXiv.2301.10655 (Access: Open)
https://doi.org/10.1103/PhysRevLett.131.243402 (Access: Open)

BibTeX

@article{69c552785bd74a65b5e1a64b5e32ff7c,
title = "Excited-State Phase Diagram of a Ferromagnetic Quantum Gas",
abstract = " The ground-state phases of a quantum many-body system are characterized by an order parameter, which changes abruptly at quantum phase transitions when an external control parameter is varied. Interestingly, these concepts may be extended to excited states, for which it is possible to define equivalent excited-state quantum phase transitions. However, the experimental mapping of a phase diagram of excited quantum states has not yet been demonstrated. Here we present the experimental determination of the excited-state phase diagram of an atomic ferromagnetic quantum gas, where, crucially, the excitation energy is one of the control parameters. The obtained phase diagram exemplifies how the extensive Hilbert state of quantum many-body systems can be structured by the measurement of well-defined order parameters. ",
keywords = "cond-mat.quant-gas, physics.atom-ph, quant-ph",
author = "Bernd Meyer-Hoppe and Fabian Anders and Polina Feldmann and Luis Santos and Carsten Klempt",
note = "We thank A. Smerzi, L. Pezz`e, and M. Gessner for inspiring discussions. We acknowledge financial support from the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation)—Project-ID 274200144—SFB 1227 DQ-mat within the project A02 and under Germany{\textquoteright}s Excellence Strategy EXC-2123 QuantumFrontiers—390837967. F. A. and B. M.-H. acknowledge support from the Hannover School for Nanotechnology (HSN). P. F. acknowledges support from the Canada First Research Excellence Fund, Quantum Materials and Future Technologies Program. B.M.-H. and F. A. performed the experiments. B. M.-H., F. A., and P. F. analyzed the data. C. K. and L. S. conceived and designed the experiments with all authors contributing. The manuscript was written by all authors.",
year = "2023",
month = dec,
doi = "10.48550/arXiv.2301.10655",
language = "English",
volume = "131",
journal = "Physical Review Letters",
issn = "0031-9007",
publisher = "American Physical Society",
number = "24",
}