Green’s function approach to the Bose–Hubbard model with disorder
We analyse the distinction between the three different ground states presented by a system of spinless bosons with short-range interactions submitted to a random potential using the disordered Bose–Hubbard model. The criteria for identifying the superfluid, the Mott-insulator, and the Bose-glass pha...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
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IOP Publishing
2021-01-01
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| Series: | New Journal of Physics |
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| Online Access: | https://doi.org/10.1088/1367-2630/ac15b3 |
| _version_ | 1827872818375688192 |
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| author | R S Souza Axel Pelster F E A dos Santos |
| author_facet | R S Souza Axel Pelster F E A dos Santos |
| author_sort | R S Souza |
| collection | DOAJ |
| description | We analyse the distinction between the three different ground states presented by a system of spinless bosons with short-range interactions submitted to a random potential using the disordered Bose–Hubbard model. The criteria for identifying the superfluid, the Mott-insulator, and the Bose-glass phases at finite temperatures are discussed for small values of the kinetic energy associated with the tunnelling of particles between potential wells. Field theoretical considerations are applied in order to construct a diagrammatic hopping expansion to the finite-temperature Green’s function. By performing a summation of subsets of diagrams we are able to find the condition to the long-range correlations which leads to the phase boundary between superfluid and insulating phases. The perturbative expression to the local correlations allows us to calculate an approximation to the single-particle density of states of low-energy excitations in the presence of small hopping, which characterizes unambiguously the distinction between the Mott-insulator and the Bose-glass phases. We obtain the phase diagram for bounded on-site disorder. It is demonstrated that our analysis is capable of going beyond the mean-field theory results for the classification of these different ground states. |
| first_indexed | 2024-03-12T16:29:02Z |
| format | Article |
| id | doaj.art-fd303a30a20e465f84ef78db6879b0c5 |
| institution | Directory Open Access Journal |
| issn | 1367-2630 |
| language | English |
| last_indexed | 2024-03-12T16:29:02Z |
| publishDate | 2021-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | New Journal of Physics |
| spelling | doaj.art-fd303a30a20e465f84ef78db6879b0c52023-08-08T15:37:08ZengIOP PublishingNew Journal of Physics1367-26302021-01-0123808300710.1088/1367-2630/ac15b3Green’s function approach to the Bose–Hubbard model with disorderR S Souza0https://orcid.org/0000-0001-9688-7301Axel Pelster1F E A dos Santos2Departamento de Física, Universidade Federal de São Carlos , 13565-905 São Carlos, SP, BrazilPhysics Department and Research Center OPTIMAS, Technische Universität Kaiserslautern , 67663 Kaiserslautern, GermanyDepartamento de Física, Universidade Federal de São Carlos , 13565-905 São Carlos, SP, BrazilWe analyse the distinction between the three different ground states presented by a system of spinless bosons with short-range interactions submitted to a random potential using the disordered Bose–Hubbard model. The criteria for identifying the superfluid, the Mott-insulator, and the Bose-glass phases at finite temperatures are discussed for small values of the kinetic energy associated with the tunnelling of particles between potential wells. Field theoretical considerations are applied in order to construct a diagrammatic hopping expansion to the finite-temperature Green’s function. By performing a summation of subsets of diagrams we are able to find the condition to the long-range correlations which leads to the phase boundary between superfluid and insulating phases. The perturbative expression to the local correlations allows us to calculate an approximation to the single-particle density of states of low-energy excitations in the presence of small hopping, which characterizes unambiguously the distinction between the Mott-insulator and the Bose-glass phases. We obtain the phase diagram for bounded on-site disorder. It is demonstrated that our analysis is capable of going beyond the mean-field theory results for the classification of these different ground states.https://doi.org/10.1088/1367-2630/ac15b3Green’s functionBose–Hubbard HamiltoniandisordersuperfluidMott insulatorBose glass |
| spellingShingle | R S Souza Axel Pelster F E A dos Santos Green’s function approach to the Bose–Hubbard model with disorder New Journal of Physics Green’s function Bose–Hubbard Hamiltonian disorder superfluid Mott insulator Bose glass |
| title | Green’s function approach to the Bose–Hubbard model with disorder |
| title_full | Green’s function approach to the Bose–Hubbard model with disorder |
| title_fullStr | Green’s function approach to the Bose–Hubbard model with disorder |
| title_full_unstemmed | Green’s function approach to the Bose–Hubbard model with disorder |
| title_short | Green’s function approach to the Bose–Hubbard model with disorder |
| title_sort | green s function approach to the bose hubbard model with disorder |
| topic | Green’s function Bose–Hubbard Hamiltonian disorder superfluid Mott insulator Bose glass |
| url | https://doi.org/10.1088/1367-2630/ac15b3 |
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