Quantum coherence and ground-state phase transition in a four-chain Bose-Hubbard model
Quantum coherence and ground-state phase transition in a four-chain Bose-Hubbard model
复制标题
四链 Bose-Hubbard 模型中的量子相干性和基态相变
DOI：
10.1088/1572-9494/ac0427
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发表时间：
2021
影响因子：
3.1
通讯作者：
Song Ya-Fei
中科院分区：
文献类型：
--
作者：
Wang Ji-Guo;Guo Lin-Qi;Song Ya-Fei
研究了具有长程相互作用的四链玻色-哈伯德模型的量子相干性和基态相变。在一个特殊的四链玻色-哈伯德模型中，即每条链只有一个光学势，我们发现了四种基态位相。研究了无序、在位相互作用和长程相互作用对量子相干性的影响。对于不存在长程相互作用的系统，随着在位相互作用的增加，量子相干性从一个周期振荡变为两个周期振荡。考虑到长程相互作用，量子相干又回到一个周期振荡。在位相互作用本身抑制了量子相干，在位相互作用和长程相互作用共同增强了弱无序的量子相干。如果无序强度增加超过临界值，它们开始抑制量子相干性。在规则的四链玻色-哈伯德模型中，即每条链都有多个光学势，用集团Gutzwiller平均场方法得到了基态相变。发现了奇异的基态相，即超流相、整体Mott绝缘体相、超固相和空穴绝缘体相。对于小的比率β= t/t，漏洞绝缘体相和超固相的组合以每个位点的半整数填充来扩展瓣。
We study the quantum coherence and ground-state phase transition of a four-chain Bose–Hubbard model with the long-range interaction. In a special four-chain Bose–Hubbard model, ie, each chain only has one optical potential, four types of the ground-state phases are discovered. The effects of the disorder, the on-site interaction and the long-range interaction on the quantum coherence are studied. For the system without the long-range interaction, the quantum coherence changes from one periodic oscillation to two periodic oscillations as the on-site interaction increases. By considering the long-range interaction, the quantum coherence goes back to one periodic oscillation again. The on-site interaction itself suppresses the quantum coherence, both the on-site interaction and long-range interaction together enhance the quantum coherence with the weak disorder. If the disorder strength is increased beyond a critical value, they start to suppress the quantum coherence. In a regular four-chain Bose–Hubbard model, ie, each chain has many optical potentials, the ground-state phase transitions are obtained by using the cluster Gutzwiller mean-field method. Exotic ground-state phases are found, ie, superfluid phase, integer Mott insulator phase, supersolid phase and loophole insulator phase. The combination of the loophole insulator phase and the supersolid phase expands the lobes with the half-integer filling per site for the small ratio β= t∥/t⊥.