Quantum coherence and ground-state phase transition in a four-chain Bose-Hubbard model

• 作者: Ji-Guo Wang Lin-Qi Guo Ya-Fei Song
• 来源期刊: 理论物理通讯（英文版）
• 年，卷（期）: 2021,（8）
• 所属期刊栏目: CONDENSED MATTER THEORY
• 页码范围: 182-188
• 页数: 7页
• 语种: 英文

摘要

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,i.e.,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,i.e.,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,i.e.,superfluid phase,integer Mort 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⊥.