Superfluid behaviour of a two-dimensional Bose gas - Archive ouverte HAL Accéder directement au contenu
Article Dans Une Revue Nature Physics Année : 2012

Superfluid behaviour of a two-dimensional Bose gas

Résumé

Owing to thermal fluctuations, two-dimensional (2D) systems cannot undergo a conventional phase transition associated with the breaking of a continuous symmetry1. Nevertheless they may exhibit a phase transition to a state with quasi-long-range order via the Berezinskii–Kosterlitz–Thouless (BKT) mechanism2. A paradigm example is the 2D Bose fluid, such as a liquid helium film3, which cannot condense at non-zero temperature although it becomes superfluid above a critical phase space density. The quasi-long-range coherence and the microscopic nature of the BKT transition were recently explored with ultracold atomic gases4,5,6. However, a direct observation of superfluidity in terms of frictionless flow is still missing for these systems. Here we probe the superfluidity of a 2D trapped Bose gas using a moving obstacle formed by a micrometre-sized laser beam. We find a dramatic variation of the response of the fluid, depending on its degree of degeneracy at the obstacle location.

Dates et versions

hal-03740936 , version 1 (30-07-2022)

Identifiants

Citer

Rémi Desbuquois, Lauriane Chomaz, Tarik Yefsah, Julian Léonard, Jérôme Beugnon, et al.. Superfluid behaviour of a two-dimensional Bose gas. Nature Physics, 2012, 8 (9), pp.645--648. ⟨10.1038/nphys2378⟩. ⟨hal-03740936⟩
8 Consultations
0 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More