| Title | Conserving and gapless Hartree-Fock-Bogoliubov theory for the three-dimensional dilute Bose gas |
| Authors | Zhang, Ya-Hui Li, Dingping |
| Affiliation | Peking Univ, Dept Phys, Beijing 100871, Peoples R China. |
| Keywords | LOW-TEMPERATURE PROPERTIES GROUND-STATE ENERGY EINSTEIN CONDENSATION HARD SPHERES GAUSSIAN APPROXIMATION SYSTEM TRANSITION HELIUM BOSONS |
| Issue Date | 2013 |
| Publisher | physical review a |
| Citation | PHYSICAL REVIEW A.2013,88,(5). |
| Abstract | The excitation spectrum for the three-dimensional Bose gas in the Bose-Einstein condensation phase is calculated nonperturbatively with the modified Hartree-Fock-Bogoliubov theory, which is both conserving and gapless. From improved Phi-derivable theory, the diagrams needed to preserve the Ward-Takahashi identity are re-summed in a systematic and nonperturbative way. It is valid up to the critical temperature where the dispersion relation of the low-energy excitation spectrum changes from linear to quadratic. Because including the higher-order fluctuation, the results show significant improvement on the calculation of the shift of critical temperature with other conserving and gapless theories. |
| URI | http://hdl.handle.net/20.500.11897/296577 |
| ISSN | 1050-2947 |
| DOI | 10.1103/PhysRevA.88.053604 |
| Indexed | SCI(E) EI |
| Appears in Collections: | 物理学院 |
