Pixley J H, Cole William S, Spielman I B, Rizzi Matteo, Sarma S Das
Condensed Matter Theory Center and Joint Quantum Institute, Department of Physics, University of Maryland, College Park, Maryland 20742-4111 USA.
Department of Physics and Astronomy, Center for Materials Theory, Rutgers University, Piscataway, NJ 08854 USA.
Phys Rev A (Coll Park). 2017 Oct;96(4). doi: 10.1103/physreva.96.043622.
We study the odd integer filled Mott phases of a spin-1 Bose-Hubbard chain and determine their fate in the presence of a Raman induced spin-orbit coupling which has been achieved in ultracold atomic gases; this system is described by a quantum spin-1 chain with a spiral magnetic field. The spiral magnetic field initially induces helical order with either ferromagnetic or dimer order parameters, giving rise to a spiral paramagnet at large field. The spiral ferromagnet-to-paramagnet phase transition is in a novel universality class, with critical exponents associated with the divergence of the correlation length and the order parameter susceptibility . We solve the effective spin model exactly using the density matrix renormalization group, and compare with both a large- classical solution and a phenomenological Landau theory. We discuss how these exotic bosonic magnetic phases can be produced and probed in ultracold atomic experiments in optical lattices.
我们研究了自旋为1的玻色-哈伯德链的奇数整数填充莫特相，并确定了在超冷原子气体中已实现的拉曼诱导自旋-轨道耦合存在下它们的命运；该系统由具有螺旋磁场的量子自旋-1链描述。螺旋磁场最初会诱导出具有铁磁或二聚体序参量的螺旋序，在大场时产生螺旋顺磁体。螺旋铁磁体到顺磁体的相变属于一个新的普适类，具有与关联长度发散和序参量磁化率相关的临界指数。我们使用密度矩阵重整化群精确求解有效自旋模型，并与大N经典解和唯象朗道理论进行比较。我们讨论了如何在光学晶格中的超冷原子实验中产生和探测这些奇异的玻色子磁相。
