Quantum phase transition in one-dimensional Bose-Einstein condensates with attractive interactions
Quantum phase transition in one-dimensional Bose-Einstein condensates with attractive interactions
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DOI：
10.1103/physreva.67.013608
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发表时间：
2003-01-01
影响因子：
2.9
通讯作者：
Ueda, M
中科院分区：
文献类型：
--
作者：
Kanamoto, R;Saito, H;Ueda, M
受Feshbach方法的启发，我们研究了一维环上玻色-爱因斯坦凝聚的基态和低激发态随相互作用强度的变化. Gross-Pitaevskii平均场理论预言了均匀凝聚体和亮孤子之间的量子相变，以及临界点处Bogoliubov激发谱中的无隙奇异尖点。然而，精确的对角化揭示了在临界点处存在能隙，在那里奇异性被量子涨落模糊。
Motivated by the recent development of the Feshbach technique, we studied the ground and low-lying excited states of attractive Bose-Einstein condensates on a one-dimensional ring as a function of the strength of interactions. The Gross-Pitaevskii mean-field theory predicts a quantum phase transition between a uniform condensate and a bright soliton, and a gapless singular cusp in the Bogoliubov excitation spectrum at the critical point. However, the exact diagonalization reveals the presence of an energy gap at the critical point, where the singularity is smeared by quantum fluctuations.