Strong and Electromagnetic Decays of The DD-wave Heavy Mesons

We calculate the $\pi$, $\rho$, $\omega$, and $\gamma$ coupling constants between the heavy meson doublets $(1^-,2^-)$ and (0^-,1^-)/(0^+,1^+) within the framework of the light-cone QCD sum rule at the leading order of heavy quark effective theory. Most of the sum rules are stable with the variations of the Borel parameter and the continuum threshold. Then we calculate the strong and electromagnetic decay widths of the $(1^-,2^-)$ D-wave heavy mesons. Their total widths are around several tens of MeV, which is helpful in the future experimental search.Comment: 20 pages, 13 figure

Simulating Z_2 topological insulators with cold atoms in a one-dimensional optical lattice

We propose an experimental scheme to simulate and detect the properties of time-reversal invariant topological insulators, using cold atoms trapped in one-dimensional bichromatic optical lattices. This system is described by a one-dimensional Aubry-Andre model with an additional SU(2) gauge structure, which captures the essential properties of a two-dimensional Z2 topological insulator. We demonstrate that topologically protected edge states, with opposite spin orientations, can be pumped across the lattice by sweeping a laser phase adiabatically. This process constitutes an elegant way to transfer topologically protected quantum states in a highly controllable environment. We discuss how density measurements could provide clear signatures of the topological phases emanating from our one-dimensional system.Comment: 5 pages +, 3 figures, to appear in Physical Review

A Robust Quantum Random Access Memory

A "bucket brigade" architecture for a quantum random memory of $N=2^n$ memory cells needs $n(n+5)/2$ times of quantum manipulation on control circuit nodes per memory call. Here we propose a scheme, in which only average $n/2$ times manipulation is required to accomplish a memory call. This scheme may significantly decrease the time spent on a memory call and the average overall error rate per memory call. A physical implementation scheme for storing an arbitrary state in a selected memory cell followed by reading it out is discussed.Comment: 5 pages, 3 figure

Probing Half-odd Topological Number with Cold Atoms in a Non-Abelian Optical Lattice

We propose an experimental scheme to probe the contribution of a single Dirac cone to the Hall conductivity as half-odd topological number sequence. In our scheme, the quantum anomalous Hall effect as in graphene is simulated with cold atoms trapped in an optical lattice and subjected to a laser-induced non-Abelian gauge field. By tuning the laser intensity to change the gauge flux, the energies of the four Dirac points in the first Brillouin zone are shifted with each other and the contribution of the single Dirac cone to the total atomic Hall conductivity is manifested. We also show such manifestation can be experimentally probed with atomic density profile measurements.Comment: 5 pages, 3 figure