Quantum hydrodynamical instabilities in two-dimensional Bose gases

• Grant number: 22/02709-6
• Support Opportunities: Research Grants - Initial Project
• Start date: February 01, 2023
• End date: January 31, 2028
• Field of knowledge: Physical Sciences and Mathematics - Physics - Atomic and Molecular Physics
• Principal Investigator: Patrícia Christina Marques Castilho
• Grantee: Patrícia Christina Marques Castilho
• Host Institution: Instituto de Física de São Carlos (IFSC). Universidade de São Paulo (USP). São Carlos , SP, Brazil
• Associated researchers: André Cidrim Santos ; Giacomo Roati ; Kilvia Mayre Farias ; Tommaso Macri
• Associated research grant(s): 23/14887-9 - Quantum vortex dynamics in two-dimensional atomic superfluids (QuVort2D), AP.R SPRINT
• Associated scholarship(s): 25/04611-1 - Radiofrequency chain for performing hyperfine state transfers, BP.IC; 24/11777-0 - Transition from three- to two-dimensional quantum gases, BP.MS; 24/04325-6 - A crossed optical dipole trap for all-optical production of Bose-Einstein condensates, BP.IC; 23/07276-3 - A magnetic field for tunning Feshbach resonances in 2D Bose gases, BP.IC

Abstract

In low dimensional systems, thermal and quantum fluctuations have a more predominant role inhibiting the achievement of long-range order for any finite temperature. As a consequence, usual second-order phase transitions, such as the freezing of water of the Bose-Einstein condensation in a system of bosonic particles, are forbidden in lower dimensions. Two-dimensional (2D) systems are interesting because a quasi long-range order can be established via another kind of phase transition, the Berezinskii-Kosterlitz-Thouless (BKT) transition, resulting from the pairing of topological defects below a critical temperature. For the case of a weakly-interacting two-dimensional Bose gas, superfluidity can be restored via the BKT transition which will exhibit a completely different behavior from its counterpart in three-dimensions. In this project, we will study the superfluid properties of a two-dimensional Bose gas of potassium-39 atoms via the onset of the quantum analogue of two of the most fundamental hydrodynamic instabilities, the Rayleigh-Taylor and the Kelvin-Helmholtz instabilities. For that, we will build up a new experimental system combining the latest technologies developed for ultracold atom experiments enabling to trigger the quantum hydrodynamic instabilities and to follow the system's long-time evolution. (AU)