Dipolar droplets
Danny Baillie (University of Otago, New Zealand)
Experiments with Bose-Einstein condensates of dysprosium [1] and erbium [2] atoms have observed the formation of dilute quantum gas droplets that can preserve their form, even in the absence of any external confinement [3]. These droplets are stabilized by Lee-Huang-Yang (LHY) quantum fluctuation corrections to meanfield theory [4]. We discuss the regimes in which such self-bound droplet states are stable [5], and examine the properties of their collective excitations. Notably we observe that the elongated filament-shaped droplets act as a quasi-one-dimensional waveguide along which low angular momentum phonons propagate [6].
References
[1] H. Kadau, M. Schmitt, M. Wenzel, C. Wink, T. Maier, I. Ferrier-Barbut, and T. Pfau, Nature 530, 194 (2016).
[2] L. Chomaz, S. Baier, D. Petter, M. J. Mark, F. Wächtler, L. Santos, and F. Ferlaino, Phys. Rev. X 6, 041039 (2016).
[3] M. Schmitt, M. Wenzel, F. Böttcher, I. Ferrier-Barbut, and T. Pfau, Nature 539, 259 (2016).
[4] T. D. Lee, K. Huang, and C. N. Yang, Phys. Rev. 106, 1135 (1957).
[5] D. Baillie, R. M. Wilson, R. N. Bisset, and P. B. Blakie, Phys. Rev. A 94, 021602(R) (2016).
[6] D. Baillie, R. M. Wilson, and P. B. Blakie, arXiv:1703.07927.