2,069 research outputs found
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
Optical rotation of heavy hole spins by non-Abelian geometrical means
A non-Abelian geometric method is proposed for rotating of heavy hole spins
in a singly positive charged quantum dot in Voigt geometry. The key ingredient
is the delay-dependent non-Abelian geometric phase, which is produced by the
nonadiabatic transition between the two degenerate dark states. We demonstrate,
by controlling the pump, the Stokes and the driving fields, that the rotations
about - and -axes with arbitrary angles can be realized with high
fidelity. Fast initialization and heavy hole spin state readout are also
possible.Comment: 7 pages, 6 figure
The first Chinese student space shuttle getaway special program
The first Chinese Getaway Special program is described. Program organization, the student proposal evaluation procedure, and the objectives of some of the finalist's experiments are covered. The two experiments selected for eventual flight on the space shuttle are described in detail. These include: (1) the control of debris in the cabin of the space shuttle; and (2) the solidification of two immiscible liquids in space
Long-range adiabatic quantum state transfer through a tight-binding chain as a quantum data bus
We introduce a scheme based on adiabatic passage that allows for long-range
quantum communication through tight-binding chain with always-on interaction.
By adiabatically varying the external gate voltage applied on the system, the
electron can be transported from the sender's dot to the aim one.We numerically
solve the Schr\"odinger equation for a system with a given number of quantum
dots. It is shown that this scheme is a simple and efficient protocol to
coherently manipulate the population transfer under suitable gate pulses. The
dependence of the energy gap and the transfer time on system parameters is
analyzed and shown numerically. Our method provides a guidance for future
realization of adiabatic quantum state transfer in experiments.Comment: 7 pages, 5 figures. arXiv admin note: text overlap with
arXiv:1206.671
- …