Umucalılar R O, Iskin M
Department of Physics, Koç University, Rumelifeneri Yolu, 34450 Sarıyer, Istanbul, Turkey.
Department of Physics, Mimar Sinan Fine Arts University, 34380 Şişli, Istanbul, Turkey.
Phys Rev Lett. 2017 Aug 25;119(8):085301. doi: 10.1103/PhysRevLett.119.085301.
The competition between the length scales associated with the periodicity of a lattice potential and the cyclotron radius of a uniform magnetic field is known to have dramatic effects on the single-particle properties of a quantum particle, e.g., the fractal spectrum is known as the Hofstadter butterfly. Having this intricate competition in mind, we consider a two-component Fermi gas on a square optical lattice with opposite synthetic magnetic fields for the components, and study its effects on the many-body BCS-pairing phenomenon. By a careful addressing of the distinct superfluid transitions from the semimetal, quantum spin-Hall insulator, or normal phases, we explore the low-temperature phase diagrams of the model, displaying lobe structures that are reminiscent of the well-known Mott-insulator transitions of the Bose-Hubbard model.
晶格势周期性相关的长度尺度与均匀磁场的回旋半径之间的竞争，已知会对量子粒子的单粒子性质产生显著影响，例如，分形谱就是著名的霍夫施塔特蝴蝶。考虑到这种复杂的竞争关系，我们研究了在具有相反合成磁场的方形光学晶格上的双组分费米气体，并探讨其对多体BCS配对现象的影响。通过仔细研究从半金属、量子自旋霍尔绝缘体或正常相的不同超流转变，我们探索了该模型的低温相图，其呈现出的叶状结构让人联想到玻色 - 哈伯德模型中著名的莫特绝缘体转变。
