Chiral p-wave pairing of ultracold fermionic atoms due to a quadratic band touching

• 来源期刊: 中国物理B（英文版）
• 关键词: degenerate cold fermionic atoms topological states Majorana fermions
• 年，卷（期）: 2018,（2）
• 页码范围: 215-219
• 页数: 5页
• 语种: 英文
• DOI: 10.1088/1674-1056/27/2/027402

摘要

We study the superfuild ground state of ultracold fermions in optical lattices with a quadratic band touching.Examples are a checkerboard lattice around half filling and a kagome lattice above one third filling.Instead of pairing between spin states,here we focus on pairing interactions between different orbital states.We find that our systems have only odd-parity (orbital) pairing instability while the singlet (orbital) pairing instability vanishes thanks to the quadratic band touching.In the mean field level,the ground state is found to be a chiral p-wave pairing superfluid (mixed with finite f-wave pairing order-parameters) which supports Majorana fermions.