Excited-state phase diagram of a ferromagnetic quantum gas

verfasst von
Bernd Meyer-Hoppe, Fabian Anders, Polina Feldmann, Luis Santos, Carsten Klempt

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.

Quantum Atom Optics
Institut für Theoretische Physik
Institut für Quantenoptik
SFB 1227: Designte Quantenzustände der Materie (DQ-mat)
Externe Organisation(en)
University of British Columbia
Elektronisch veröffentlicht (E-Pub)