Bogoliubov excitations in a Bose-Hubbard model on a hyperhoneycomb lattice

• 来源期刊: 中国物理B（英文版）
• 关键词: hyperhoneycomb lattice Mott-superfluid transition Bogoliubov excitations nodal-loop
• 年，卷（期）: 2018,（5）
• 页码范围: 108-114
• 页数: 7页
• 语种: 英文
• DOI: 10.1088/1674-1056/27/5/050302

摘要

We study the topological properties of Bogoliubov excitation modes in a Bose-Hubbard model of three-dimensional (3D) hyperhoneycomb lattices.For the non-interacting case,there exist nodal loop excitations in the Bloch bands.As the on-site repulsive interaction increases,the system is first driven into the superfluid phase and then into the Mott-insulator phase.In both phases,the excitation bands exhibit robust nodal-loop structures and bosonic surface states.From a topology point of view,these nodal-loop excitation modes may be viewed as a permanent fingerprint left in the Bloch bands.