Superfluid Filaments of Dipolar Bosons in Free Space
Authors: Salasnich L., Cinti F., Cappellaro A., Macrì T.
Autors Affiliation: National Institute for Theoretical Physics (NITheP), Stellenbosch 7600, South Africa; Institute of Theoretical Physics, Stellenbosch University, Stellenbosch 7600, South Africa; Dipartimento di Fisica e Astronomia Galileo Galilei and CNISM, Università di Padova, via Marzolo 8, 35131 Padova, Italy; CNR-INO, via Nello Carrara, 1–50019 Sesto Fiorentino, Italy; Departamento de Física Teórica e Experimental, Universidade Federal do Rio Grande do Norte and International Institute of Physics, 59078-970 Natal, Rio Grande do Norte, Brazil
Abstract: We systematically investigate the zero temperature phase diagram of bosons interacting via dipolar interactions in three dimensions in free space via path integral Monte Carlo simulations with a few hundreds of particles and periodic boundary conditions based on the worm algorithm. Upon increasing the strength of the dipolar interaction and at sufficiently high densities we find a wide region where filaments are stabilized along the direction of the external field. Most interestingly by computing the superfluid fraction we conclude that the superfluidity is anisotropic and is greatly suppressed along the orthogonal plane. Finally, we perform simulations at finite temperature confirming the stability of the filaments against thermal fluctuations and provide an estimate of the superfluid fraction in the weak coupling limit in the framework of the Landau two-fluid model.
Journal/Review: PHYSICAL REVIEW LETTERS
Volume: 119 (21) Pages from: 215302-1 to: 215302-6
KeyWords: bose-einstein condensation; path integral quantum monte carlo;