The structure of paired boson superfluids

This paper investigates classical and quantum mechanical models of superfluids and superfluid vortices using the Ginsburg Landau energy equation. Specifically, two types of superfluids are considered, ordinary superfluids where single bosons condense to form a strongly correlated system and superfluids where pairs of bosons condense to form a strongly correlated system while the single bosons remain uncondensed. First, the classical minimum energy configuration for an ordinary superfluid with and without a vortex was calculated. Additionally, the phase diagram for the exotic superfluid created by treating single bosons separately from pairs of bosons was determined as was the minimum energy state for each phase. Using these results, I then quantized the Ginsburg-Landau energy and investigated the possibility of excited states by creating small quantum mechanical oscillations about the classical minima. In the uniform superfluid, both the ordinary and exotic superfluids are able to support low energy excitations in the form of sound waves. In addition, the exotic superfluid has a gapped excitation that is a remanant of the uncondensed boson. Finally, the formalism for studying the modes of small oscillation about the classical minimum was developed for the superfluid vortex.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Physics.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2004

Author dc:creator

• Daniel, Mara S. (Mara Stephanie), 1982-

Advisor dc:contributor.advisor

• Senthil Todadri.

• Physics.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/32735

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/32735