Theoretical study of Bose-Einstein condensates using a new self-consistent perturbation expansion
Project/Area Number |
22540356
|
Research Category |
Grant-in-Aid for Scientific Research (C)
|
Allocation Type | Single-year Grants |
Section | 一般 |
Research Field |
Condensed matter physics II
|
Research Institution | Hokkaido University |
Principal Investigator |
KITA Takafumi 北海道大学, 大学院・理学研究院, 准教授 (20186224)
|
Project Period (FY) |
2010 – 2012
|
Project Status |
Completed (Fiscal Year 2012)
|
Budget Amount *help |
¥4,160,000 (Direct Cost: ¥3,200,000、Indirect Cost: ¥960,000)
Fiscal Year 2012: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000)
Fiscal Year 2011: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000)
Fiscal Year 2010: ¥2,080,000 (Direct Cost: ¥1,600,000、Indirect Cost: ¥480,000)
|
Keywords | ボーズ-アインシュタイン凝縮 / 自発的対称性の破れ / 場の量子論 / ボーズ・アインシュタイン凝縮 / グリーン関数 / ボゴリュボフ励起 / 超流動 / 超伝導 / BCS-BECクロスオーバー / ゴールドストーンの定理 / 南部-ゴールドストーン・ボゾン / 自己無撞着摂動展開 / 保存近似 / 密度揺らぎ |
Research Abstract |
A new self-consistent perturbation expansion, which was developed recently by the principal investigator, has been used to clarify basic properties of a single-component Bose-Einstein condensate. A widely accepted viewpoint on the elementary excitations of the system is that the single- and two-particle excitations are identical and described by the gapless excitation of the Bogoliubov theory. We have found, however, that the two excitations are different from each other. It is also found that the well-known expression on the ground-state energy of a dilute Bose gas by Lee, Huang and Yang should be modified due to a new class of Feynman diagrams for the self-energy.
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Report
(4 results)
Research Products
(33 results)