Intertwined superfluidity and density wave order in a p -orbital Bose condensate

We study a continuum model of the weakly interacting Bose gas in the presence of an external field with minima forming a triangular lattice. The second lowest band of the single-particle spectrum ( p band) has three minima at nonzero momenta. We consider a metastable Bose condensate at these momenta...

Full description

Saved in:
Bibliographic Details
Published in:Physical review. B 2019-01, Vol.99 (1), p.1, Article 014504
Main Authors: Lieu, Simon, Ho, Andrew F., Lee, Derek K. K., Coleman, Piers
Format: Article
Language:English
Subjects:
Condensates
Continuum modeling
Fluids
Helium
Lattice vibration
Order parameters
P band
Superfluidity
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:We study a continuum model of the weakly interacting Bose gas in the presence of an external field with minima forming a triangular lattice. The second lowest band of the single-particle spectrum ( p band) has three minima at nonzero momenta. We consider a metastable Bose condensate at these momenta and find that, in the presence of interactions that vary slowly over the lattice spacing, the order parameter space is isomorphic to S5. We show that the enlarged symmetry leads to the loss of topologically stable vortices, as well as two extra gapless modes with quadratic dispersion. The former feature implies that this non-Abelian condensate is a “failed superfluid” that does not undergo a Berezinskii-Kosterlitz-Thouless (BKT) transition. Order-by-disorder splitting appears suppressed, implying that signatures of the S5 manifold ought to be observable at low temperatures.
ISSN:2469-9950
2469-9969
DOI:10.1103/PhysRevB.99.014504