Ultracold fermions in a graphene-type optical lattice Kean Loon Lee (李健伦), Benot Grmaud, Rui Han (韩睿), Berthold-Georg Englert, and Christian Miniatura Phys. Rev. A 80, 043411 (Published October 19, 2009) Two highly active fields of physics have merged in recent years, as researchers work to build models of condensed matter systems using ultracold atoms suspended in optical lattices. Graphene provides an environment for many intriguing physics problems, with its massless fermions, unusually high carrier mobility, and anomalous quantum Hall behavior. Now, Kean Loon Lee and colleagues at the National University of Singapore, and at Ecole Normale Suprieure and Institut Non Linaire de Nice in France, report in Physical Review A their theoretical studies of ultracold atoms arranged in a hexagonal graphenelike optical lattice. When atoms are loaded into optical traps researchers can control their position and the strength of their interactions. The authors model a two-dimensional honeycomb lattice of traps created by the interference of three laser beams. They then carry out tight-binding calculations of the band structure to show that a signature of graphenetransport of massless excitationscould indeed exist in this analogous system. Lee et al. also study the hopping of nearest-neighbor atoms and the influence of lattice distortions, providing a useful guidepost to future experimental efforts. David Voss
标签: 超冷
