Probe of Three-Dimensional Chiral Topological Insulators in an Optical   Lattice
  We propose a feasible experimental scheme to realize a three-dimensional chiral topological insulator with cold fermionic atoms in an optical lattice, which is characterized by an integer topological invariant distinct from the conventional $Z_2$ topological insulators and has a remarkable macroscopic zero-energy flat band. To probe its property, we show that its characteristic surface states---the Dirac cones---can be probed through time-of-flight imaging or Bragg spectroscopy and the flat band can be detected via measurement of the atomic density profile in a weak global trap. The realization of this novel topological phase with a flat band in an optical lattice will provide a unique experimental platform to study the interplay between interaction and topology and open new avenues for application of topological states. 
Sheng-Tao Wang, Dong-Ling Deng, Lu-Ming Duan
cond-mat.str-el cond-mat.mes-hall cond-mat.quant-gas quant-ph