Calculation of Canonical Properties and Excited States by Path Integral Numerical Methods
2011 (English)In: Contributions to Plasma Physics, ISSN 0863-1042, E-ISSN 1521-3986, Vol. 51, no 4, 382-385 p.Article in journal (Refereed) Published
Path integral Monte Carlo method in the expanded ensemble is used for calculation of the ratio of partition functions for different classes of permutations treating the problem of several interacting identical particles (fermions) in an external field. Wang-Landau algorithm is used for adjustment of balancing factors. For systems consisting of greater than two number of particles we propose an advanced variant of our approach which implies calculation of the ratio of positive and negative contributions to the partition function. Densities and energies of the sequence of excited states starting from the ground state for a system of non interacting quantum particles are calculated in turn, one by one, by means of considering systems with artificially excluded lowest energy levels and further obtaining of the ground state of each next system constructed in this way. The idea of evaluation of densities of excited states for a quantum system with interparticle interaction by evaluating density difference between systems of different number of noninteracting Fermi-copies of the system of interest is realized in terms of cyclic expansion formalism for a simple 2D system of two spinless fermions interacting via Coulomb repulsion.
Place, publisher, year, edition, pages
2011. Vol. 51, no 4, 382-385 p.
Quantum statistics, Monte Carlo, path-integral, expanded ensembles, Wang-Landau algorithm
IdentifiersURN: urn:nbn:se:su:diva-68516DOI: 10.1002/ctpp.201010112ISI: 000290525900012OAI: oai:DiVA.org:su-68516DiVA: diva2:473425
authorCount :42012-01-052012-01-042012-01-05Bibliographically approved