Droplets and Rotons in Dipolar Bose-Einstein Condensates

Luis Santos
November 20th, 2017 LUIS SANTOS Leibniz Universität Hannover

Recent experiments are revealing novel properties of quantum gases formed by atoms with large magnetic dipole moments. I will discuss two particularly relevant features of these dipolar quantum gases that closely connect to those experiments.

In the first part, I will focus on dipolar rotons, i.e. low-energy finite-momentum excitations in dipolar condensates that resemble the well-known rotons in helium, although their physical origin is very different. I will discuss on the nature of dipolar rotons, and then I will comment in detail on recent experiments performed at Innsbruck that have revealed and characterized for the first time the creation of rotons in dipolar condensates.

In the second part I will focus on dipolar quantum droplets, i.e. dipolar condensates that remain self-bound due to the effective surface tension provided by quantum fluctuations. After discussing the general idea and key experimental results, I will comment on the theoretical description of these droplets, which describes to a large extent recent experiments. I will then focus on the peculiar nature of quantum fluctuations in 1D dipolar gases. Throughout the whole discussion I will compare in detail dipolar droplets and those formed in binary mixtures, which have been very recently realized for the first time at ICFO.

Seminar, November 20, 2017, 15:00. ICFO’s Seminar Room

Hosted by Prof. Leticia Tarruell