Schmidt K P, Dorier J, Läuchli A M, Mila F
Institute of Theoretical Physics, Ecole Polytechnique Fédérale de Lausanne, CH 1015 Lausanne, Switzerland.
Phys Rev Lett. 2008 Mar 7;100(9):090401. doi: 10.1103/PhysRevLett.100.090401. Epub 2008 Mar 3.
We show that correlated hopping of triplets, which is often the dominant source of kinetic energy in dimer-based frustrated quantum magnets, produces a remarkably strong tendency to form supersolid phases in a magnetic field. These phases are characterized by simultaneous modulation and ordering of the longitudinal and transverse magnetization, respectively. Using quantum Monte Carlo and a semiclassical approach for an effective hard-core boson model with nearest-neighbor repulsion on a square lattice, we prove, in particular, that a supersolid phase can exist even if the repulsion is not strong enough to stabilize an insulating phase at half-filling. Experimental implications for frustrated quantum antiferromagnets in a magnetic field at zero and finite temperature are discussed.
我们表明,三重态的关联跳跃(这通常是基于二聚体的受挫量子磁体中动能的主要来源)在磁场中产生了形成超固相的显著强烈趋势。这些相分别以纵向和横向磁化的同时调制和有序化为特征。通过量子蒙特卡罗方法以及对具有最近邻排斥的方形晶格上的有效硬核玻色子模型采用半经典方法,我们特别证明,即使排斥力不够强以至于无法在半填充时稳定绝缘相,超固相仍可能存在。我们还讨论了在零温和有限温度下磁场中受挫量子反铁磁体的实验意义。