Supersolid phase in two-dimensional soft-core bosons at finite temperature
Year: 2025
Authors: Peotta S., Spada G., Giorgini S., Pilati S., Recati A.
Autors Affiliation: Aalto Univ, Sch Sci, Dept Appl Phys, FI-00076 Aalto, Finland; Univ Camerino, Sch Sci & Technol, Phys Div, I-62032 Camerino, Italy; Ist Nazl Fis Nucl, Sez Perugia, I-06123 Perugia, Italy; Univ Trento, Pitaevskii BEC Ctr, Consiglio Nazl Ric INO, I-38123 Trento, Italy; Univ Trento, Dipartimento Fis, I-38123 Trento, Italy.
Abstract: The supersolid phase of soft-core bosons in two dimensions is investigated using the self-consistent HartreeFock and quantum Monte Carlo methods. An approximate phase diagram at finite temperatures is initially constructed using the mean-field approach, which is subsequently validated through precise path-integral simulations, enabling a microscopic characterization of the various phases. Superfluid and melting/freezing transitions are analyzed through the superfluid density and the long-range behavior of correlation functions associated with positional and orientational order, in accordance with the general picture of Berezinskii-Kosterlitz-Thouless transitions. A broad region at low temperatures is identified where the supersolid phase exists, separating the uniform superfluid phase from the normal quasicrystal phase. Additionally, a potential intermediate hexatic phase with quasi-long-range orientational order is identified in a narrow region between the normal solid and fluid phases. These findings establish self-consistent Hartree-Fock theory beyond the local density approximation as an effective tool, complementary to computationally intensive quantum Monte Carlo simulations, for investigating the melting of the supersolid phase and the possible emergence of the hexatic superfluid phase in bosonic systems with various interaction potentials.
Journal/Review: PHYSICAL REVIEW B
Volume: 112 (18) Pages from: 184506-1 to: 184506-22
More Information: We acknowledge support from PNRR MUR Project No. PE0000023-NQSTI; PRIN 2022 MUR project Hybrid algorithms for quantum simulators- Project No. 2022H77XB7; PRIN-PNRR 2022 MUR project UEFA-Project No. P2022NMBAJ; CINECA awards IsCc2_REASON, IsCc2_QD2DBS, and INF24_lincoln; EuroHPC Joint Undertaking for awarding access to the EuroHPC supercomputer LUMI, hosted by CSC (Finland) , through EuroHPC Development and Regular Access calls; ICSC-Centro Nazionale di Ricerca in HPC, Big Data and Quantum Computing, Project No. CN00000013 Spoke 7-Materials and Molecular Sciences, funded by the European Union under NextGenerationEU; Research Council of Finland under Grants No. 330384, No. 336369, and No. 358150; Aalto Science-IT project for the computational resources; and Provincia Autonoma di Trento. S. Peotta gratefully acknowledges the support and kind hospitality of the Pitaevskii Center for Bose-Einstein Condensation (Trento, Italy) and its members during a yearlong visit in 2023-2024. A substantial part of the work leading to this publication was carried out during this research visit.KeyWords: Quantum-theory; Transition; Simulation; Crystals; ModelDOI: 10.1103/syns-jm6w
