Hydrodynamics of superfluids confined in blocked rings and wedges

Dasgupta, Chandan and Valls, Oriol T (2009) Hydrodynamics of superfluids confined in blocked rings and wedges. In: Physical Review E, 79 (1, Par).

PDF 4.pdf - Published Version Restricted to Registered users only Download (363kB) | Request a copy

Abstract

Motivated by many recent experimental studies of nonclassical rotational inertia (NCRI) in superfluid and supersolid samples, we present a study of the hydrodynamics of a superfluid confined in the two-dimensional region (equivalent to a long cylinder) between two concentric arcs of radii b and a (b < a) subtending an angle beta, with 0 <=beta <= 2 pi. The case beta=2 pi corresponds to a blocked ring. We discuss the methodology to compute the NCRI effects and calculate these effects both for small angular velocities, when no vortices are present, and in the presence of a vortex. We find that, for a blocked ring, the NCRI effect is small and that therefore there will be a large discontinuity in the moment of inertia associated with blocking or unblocking circular paths. For blocked wedges (b=0) with beta>pi, we find an unexpected divergence of the velocity at the origin, which implies the presence of either a region of normal fluid or a vortex for any nonzero value of the angular velocity. Implications of our results for experiments on ``supersolid'' behavior in solid He-4 are discussed. A number of mathematical issues are pointed out and resolved.

Item Type:	Journal Article
Publication:	Physical Review E
Publisher:	American Physical Society
Additional Information:	Copyright of this article belongs to American Physical Society.
Keywords:	hydrodynamics;superfluid helium-4;superfluidity;vortices.
Department/Centre:	Division of Physical & Mathematical Sciences > Physics
Date Deposited:	12 Aug 2009 09:29
Last Modified:	19 Sep 2010 05:27
URI:	http://eprints.iisc.ac.in/id/eprint/19170

Actions (login required)

View Item