Solving sign problems with meron cluster algorithms : simulating field theories at non-zero chemical potential

Numerical simulation of quantum systems develop sign problems upon the introduction of a chemical potential. The sign problem thus makes many interesting physical systems very difficult to study numerically. In this thesis, two related systems which develop sign problems in this way are considered: a D-Theory representation of a 1+1 dimensional 0(3) quantum field theory with a chemical potential, and antiferromagnetic Heisenberg quantum spin ladders in a magnetic field. In both cases, meron cluster algorithms are used to completely solve the sign problem. Using these algorithms, numerical results were generated in the two models for, respectively, the particle number as a function of the chemical potential and magnetization as a function of the external field. These results are in agreement with corresponding analytic predictions.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Physics.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2001

Author dc:creator

• Scarlet, Benjamin S., 1974-

Advisor dc:contributor.advisor

• Uwe-Jens Wiese.

• 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/1721.1/8280

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/8280