Is Gamma-ray Absorption by Induced Electric Fields Important in the Pulsar Magnetospheres?

Although the unified formula for gamma-ray absorption process involving both the magnetic field and a perpendicular electric field derived by Daugherty & Lerche (1975) is correct, we argued in this paper that their conclusion that the induced electric fields are important in the pair formation process in the pulsar magnetospheres is wrong and misleading. The key point is that usually the direction of a gamma photon at the emission point observed in the laboratory frame should be (v/c, 0, [1-(v/c)^2]^{1/2}) rather than (0, 0, 1), where v is the co-rotating velocity. This emission direction is just the one which results in zero attenuation coefficient of the gamma photon. Calculation shows that after the photon has moved a distance, its direction lead to the result that the induced electric field is also of minor importance. Thus only gamma-B process is the important mechanism for the pair production in the pulsar magnetospheres. The implications of the modification by ejecting the induced electric field are also discussed.Comment: 4 pages, 2 Postscript figures, LaTeX, some miscomments on the references of Harding et al are modified, Accepted for publication in Astronomy and Astrophysics Letter

Phase diagram of two-species Bose-Einstein condensates in an optical lattice

The exact macroscopic wave functions of two-species Bose-Einstein condensates in an optical lattice beyond the tight-binding approximation are studied by solving the coupled nonlinear Schrodinger equations. The phase diagram for superfluid and insulator phases of the condensates is determined analytically according to the macroscopic wave functions of the condensates, which are seen to be traveling matter waves.Comment: 13 pages, 2 figure

Controllable Persistent Atom Current of Bose-Einstein Condensates in an Optical Lattice Ring

In this paper the macroscopic quantum states of Bose-Einstein condensates in optical lattices is studied by solving the periodic Gross-Pitaevskii equation in one-dimensional geometry. It is shown that an exact solution seen to be a travelling wave of excited macroscopic quantum states resultes in a persistent atom current which can be controlled by adjusting of the barrier height of the optical periodic potential. A critical condition to generate the travelling wave is demonstrated and we moreover propose a practical experiment to realize the persistent atom current in a toroidal atom waveguide.Comment: 9 pages, 1 figure

Self Interference of Single Electrodynamic Particle in Double Slit

It is by the long established fact in experiment and theory that electromagnetic waves, here as one component of an IED particle, passing a double slit will undergo self inference each, producing at a detector plane fringed intensities. The wave generating point charge of a zero rest mass, as the other component of the particle, is maintained a constant energy and speed by a repeated radiation reabsorption/reemission scheme, and in turn steered in direction in its linear motion by the reflected radiation field, and will thereby travel to the detector along (one of) the optical path(s) of the waves leading to a bright interference fringe. We elucidate the process formally based on first principles solutions for the IED particle and known principles for wave-matter interaction.Comment: Presentation at The 6th Int. Symp. Quantum Theory and Symmetries, Univ. Kent, 2009

Efficient Cluster Algorithm for Spin Glasses in Any Space Dimension

Spin systems with frustration and disorder are notoriously difficult to study both analytically and numerically. While the simulation of ferromagnetic statistical mechanical models benefits greatly from cluster algorithms, these accelerated dynamics methods remain elusive for generic spin-glass-like systems. Here we present a cluster algorithm for Ising spin glasses that works in any space dimension and speeds up thermalization by at least one order of magnitude at temperatures where thermalization is typically difficult. Our isoenergetic cluster moves are based on the Houdayer cluster algorithm for two-dimensional spin glasses and lead to a speedup over conventional state-of-the-art methods that increases with the system size. We illustrate the benefits of the isoenergetic cluster moves in two and three space dimensions, as well as the nonplanar chimera topology found in the D-Wave Inc.~quantum annealing machine.Comment: 5 pages, 4 figure