From spontaneous to explicit symmetry breaking in a finite-sized system: Bosonic bound states of an impurity

• URL: http://arxiv.org/abs/2412.09372v1
• Date: Thu, 12 Dec 2024 15:40:44 GMT
• Title: From spontaneous to explicit symmetry breaking in a finite-sized system: Bosonic bound states of an impurity
• Authors: L. Chergui, F. Brauneis, T. Arnone Cardinale, M. Schubert, A. G. Volosniev, S. M. Reimann,
• Abstract summary: impurity can drive a transition from a homogeneous to a localized state.<n>Low-lying modes resemble finite-size precursors of Higgs-Anderson and Nambu-Goldstone-like modes.<n>We find improved agreement between the few-body exact diagonalization results and mean-field predictions of binding with increasing boson-boson repulsion.
• Score: 0.0
• License: http://creativecommons.org/licenses/by/4.0/
• Abstract: The presence of a single attractive impurity in an ultracold repulsive bosonic system can drive a transition from a homogeneous to a localized state, as we here show for a one-dimensional ring system. In the few-body limit the localization of the bosons around the impurity, as seen in the pair correlations, is accompanied by low-lying modes that resemble finite-size precursors of Higgs-Anderson and Nambu-Goldstone-like modes. Tuning the impurity-boson mass ratio allows for the exploration of the transition from a spontaneous to an explicit breaking of the continuous rotational symmetry of the Hamiltonian. We compare the minimum of the Higgs-Anderson-like mode as a marker of the onset of localization in the few-body limit to mean-field predictions of binding. We find improved agreement between the few-body exact diagonalization results and mean-field predictions of binding with increasing boson-boson repulsion.

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