Exploring quantum quasicrystal patterns: a variational study
Abstract
We study the emergence of quasicrystal configurations produced purely by quantum fluctuations in the groundstate phase diagram of interacting bosonic systems. By using a variational meanfield approach, we determine the relevant features of the pair interaction potential that stabilize such quasicrystalline states in two dimensions. Unlike their classical counterpart, in which the interplay between only two wave vectors determines the resulting symmetries of the solutions, the quantum picture relates in a more complex way to the instabilities of the excitation spectrum. Moreover, the quantum quasicrystal patterns are found to emerge as the ground state with no need of moderate thermal fluctuations. The study extends to the exploration of the excitation properties and the possible existence of superquasicrystals, i.e. supersolidlike quasicrystalline states in which the longrange nonperiodic density profile coexist with a nonzero superfluid fraction. Our calculations show that, in an intermediate region between the homogeneous superfluid and the normal quasicrystal phases, these exotic states indeed exist at zero temperature. Comparison with full numerical simulations provides a solid verification of the variational approach adopted in this work.
 Publication:

arXiv eprints
 Pub Date:
 October 2021
 arXiv:
 arXiv:2110.12299
 Bibcode:
 2021arXiv211012299M
 Keywords:

 Condensed Matter  Quantum Gases;
 Condensed Matter  Mesoscale and Nanoscale Physics;
 Condensed Matter  Soft Condensed Matter
 EPrint:
 10 pages, 6 Figures