Thermography of the superfluid transition in a strongly interacting Fermi gas

• 成果类型: Article
• 署名作者: Yan, Zhenjie; Patel, Parth B.; Mukherjee, Biswaroop; Vale, Chris J.; Fletcher, Richard J.; Zwierlein, Martin W.
• 署名单位: Massachusetts Institute of Technology (MIT); Harvard University; Massachusetts Institute of Technology (MIT); Swinburne University of Technology; Swinburne University of Technology; University of California System; University of California Berkeley
• 刊物名称: SCIENCE
• ISSN/ISSBN: 0036-10005
• DOI: 10.1126/science.adg3430
• 发表日期: 2024-02-09
• 页码: 629-633
• 关键词: 2nd sound; transport

摘要

Heat transport can serve as a fingerprint identifying different states of matter. In a normal liquid, a hotspot diffuses, whereas in a superfluid, heat propagates as a wave called second sound. Direct imaging of heat transport is challenging, and one usually resorts to detecting secondary effects. In this study, we establish thermography of a strongly interacting atomic Fermi gas, whose radio-frequency spectrum provides spatially resolved thermometry with subnanokelvin resolution. The superfluid phase transition was directly observed as the sudden change from thermal diffusion to second-sound propagation and is accompanied by a peak in the second-sound diffusivity. This method yields the full heat and density response of the strongly interacting Fermi gas and therefore all defining properties of Landau's two-fluid hydrodynamics.