У оквиру семинара Центра за изучавање комплексних система Института за физику у Београду, у четвртак, 5. маја 2025. године у 14 часова у сали „Звонко Марић“ Института за физику у Београду, др Марија Шиндик (Центар за изучавање комплексних система, Институт за физику у Београду) одржаће предавање:
Sound in Dipolar Supersolids
САЖЕТАК:
Supersolid is an intriguing state of matter characterized by the spontaneous and simultaneous breaking of phase and continuous translational symmetry, resulting in the non-intuitive coexistence of superfluid and crystalline features. This phase has recently been realized experimentally in dipolar Bose-Einstein condensates. In one-dimensional ring-trap geometries, superolids exhibit two Goldstone modes, which can be excited by the sudden removal of a weak periodic perturbation. In this talk we will present a numerical investigation of the resulting collective oscillations using the extended Gross-Pitaevskii theory and extract the corresponding sound velocities. Comparing these with predictions from supersolid hydrodynamic theory will enable us to identify the superfluid fraction – a key parameter characterizing the supersolid phase. In the presence of persistent currents, the excitation spectrum is modified by a Doppler effect, resulting in a doubling of the sound velocities. We will demonstrate that the Doppler shifts differ for the two modes, with analytical predictions from hydrodynamics showing good agreement with Gross-Pitaevskii simulations.