A modified Bogoliubov method applied to a simple boson model
Teoretičeskaâ i matematičeskaâ fizika, Tome 190 (2017) no. 1, pp. 124-137
Cet article a éte moissonné depuis la source Math-Net.Ru
We use a non-gauge-invariant modification of the exact Hamiltonian to obtain a new Hamiltonian-like operator for a simple exactly solvable boson model. The eigenvalues of the new operator are close to those of the original Hamiltonian. We make a one-body approximation of the new two-body operator in the spirit of the Bogoliubov approximation. Because only the number operator appears, the $c$-number approximation is not required individually for the creation or annihilation operators in the ground state. For the simple model, the results using the new approximation are closer to the exact results than the usual Bogoliubov results over a wide range of parameters. The improvement increases dramatically as the model interaction strength increases.
Keywords:
modified Bogoliubov approximation.
@article{TMF_2017_190_1_a8,
author = {O. Litt and W. H. Bassichis},
title = {A~modified {Bogoliubov} method applied to a~simple boson model},
journal = {Teoreti\v{c}eska\^a i matemati\v{c}eska\^a fizika},
pages = {124--137},
year = {2017},
volume = {190},
number = {1},
language = {ru},
url = {http://geodesic.mathdoc.fr/item/TMF_2017_190_1_a8/}
}
O. Litt; W. H. Bassichis. A modified Bogoliubov method applied to a simple boson model. Teoretičeskaâ i matematičeskaâ fizika, Tome 190 (2017) no. 1, pp. 124-137. http://geodesic.mathdoc.fr/item/TMF_2017_190_1_a8/