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Programs in Physics & Physical Chemistry



Manuscript Title: A basis-set based Fortran program to solve the Gross-Pitaevskii Equation for dilute Bose gases in harmonic and anharmonic traps.
Authors: Rakesh Prabhat Tiwari, Alok Shukla
Program title: bose.x
Catalogue identifier: ADWZ_v1_0 Distribution format: tar.gz
Journal reference: Comput. Phys. Commun. 174(2006)966
Programming language: mostly Fortran 90.
Computer: PC, Sun Ultra 10, HP Alpha, IBM.
Operating system: Linux, Solaris, Tru64, AIX.
Keywords: Bose-Einstein condensation, Gross-Pitaevskii Equation, Anharmonic potential, Numerical Solutions.
PACS: 02.70.-c, 02.70.Hm, 03.75.Hh, 03.75.Nt.
Classification: 7.7.
Nature of problem: It is widely believed that the static properties of dilute Bose condensates, as obtained in atomic traps, can be described to a fairly good accuracy by the time-independent Gross-Pitaevskii equation. This program presents an efficient approach to solving this equation.
Solution method: The solutions of the Gross-Pitaevskii equation corresponding to the condensates in atomic traps are expanded as linear combinations of simple-harmonic oscillator eigenfunctions. Thus, the Gross-Pitaevskii equation which is a second-order, nonlinear, differential equation, is transformed into a matrix eigenvalue problem. Thereby, its solutions are obtained in a self-consistent manner, using methods of computational linear algebra.
Running time: Less than a minute for the examples.