Dilute quantum liquids and supersolidity in dipolar Bose-Einstein condensates

Add to your list(s) Download to your calendar using vCal

• Russell Bisset (Hannover)
• Thursday 16 May 2019, 13:45-15:00
• Theory Library.

If you have a question about this talk, please contact Mike Gunn.

Cooled to nano-Kelvin temperatures, Bose-Einstein condensates (BECs) of highly-magnetic (dipolar) atoms are now available using chromium, dysprosium and erbium. In some sense they can be thought of as quantum gases of tiny bar magnets.

While these are extremely dilute, they possess several phenomena reminiscent of conventional condensed matter systems such as liquids, ferrofluids, and superfluid helium. Among the analogue phenomena is a kind of quantum Rosensweig instability [1], weakly-interacting rotons (where the excitations’ energy-momentum relationship exhibits a local minimum) [2], dilute quantum liquids that are stabilised by quantum fluctuations [1,3], and the possibility of achieving supersolidity.

The supersolid – paradoxically exhibiting both superfluidity and density ordering at the same time – was first predicted in liquid helium around 50 years ago but has remained elusive until now.

In this talk I will review some of the recent developments with dipolar BECs, and then present our very recent experimental realisation of a proto-supersolid (note that I’m a theorist and this is the result of an experiment-theory collaboration between Pisa and Hanover) [4]. Our work was rapidly followed up by similar experiments in Stuttgart [5] and Innsbruck [6]. [1] Kadau et al., Nature 530, 194 (2016) [2] Chomaz et al., Nature Physics 14, 442 (2018) [3] Schmitt et al., Nature 539, 259 (2016) [4] Tanzi et al. Phys. Rev. Lett. 122, 130405 (2019) [5] Böttcher et al. Phys. Rev. X 9 , 011051 (2019) [6] Chomaz et al., Phys. Rev. X 9 , 021012 (2019)

This talk is part of the Theoretical Physics Seminars series.

This talk is included in these lists:

• Bham Talks
• Theoretical Physics Seminars
• Theory Library
• What's on in Physics?

Note that ex-directory lists are not shown.