Browsing by Author "MENG, HF"

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CATALYTIC INTERFACE EROSION
(1995-04-01)
MENG, HF
;
COHEN, EGD
;
物理研究所
;
Institute of Physics
GROWTH, SELF-RANDOMIZATION, AND PROPAGATION IN A LORENTZ LATTICE-GAS
(1994-10-01)
MENG, HF
;
COHEN, EGD
;
物理研究所
;
Institute of Physics
A systematic study is carried out of a Lorentz lattice gas in order to model the growth dynamics of order-disorder interfaces. In the model, a particle, initially at the origin, moves on the bonds of an initially ordered square lattice, with sites covered by periodically repeated square blocks of 1, 4, or 9 right or left scattering rotators, whose orientations change after collisions with the particle. Depending then on the initial conditions of the blocks and the particle, one observes the following: (a) the particle randomizes the rotator orientations completely, in an ever growing disordered ''liquid'' phase inside the ordered ''solid'' phase on the rest of the lattice; (b) the particle propagates suddenly after a transient randomization period as in (a); or (c) the particle propagates through the ordered lattice immediately. A simple picture for the growth of the randomized region, which proceeds via an interface of fractal dimension 0.75, is discussed. The nature of the propagation for the cases mentioned can be modified by collisions with impurities.
SUB-POISSON PHOTOELECTRON STATISTICS IN SATURATED LIGHT-ABSORPTION
(1995-10-01)
MENG, HF
;
物理研究所
;
Institute of Physics
We show that sub-Poisson photoelectrons can result from the finite relaxation time of the fundamental photoelectron-emitting entities, which could be individual atoms, or valence-band electrons, etc., depending on the type of the detectors. After identifying the precise quantum-mechanical criterion for a light without the intrinsic antibunching property, it is demonstrated that the variance to mean ratio of photoelectron counts within a fixed time period can be reduced to as small as 1/2, even for such light. The condition for strong fluctuation reduction is found to be the saturation of light absorption. Semiconductor photodetectors are considered in relative details, and their photoelectron statistics are expressed in terms of the intrinsic material parameters.
SUB-POISSON PHOTOELECTRON STATISTICS IN SATURATED LIGHT-ABSORPTION
(1995-10-01)
MENG, HF
;
交大名義發表
;
物理研究所
;
National Chiao Tung University
;
Institute of Physics
We show that sub-Poisson photoelectrons can result from the finite relaxation time of the fundamental photoelectron-emitting entities, which could be individual atoms, or valence-band electrons, etc., depending on the type of the detectors. After identifying the precise quantum-mechanical criterion for a light without the intrinsic antibunching property, it is demonstrated that the variance to mean ratio of photoelectron counts within a fixed time period can be reduced to as small as 1/2, even for such light. The condition for strong fluctuation reduction is found to be the saturation of light absorption. Semiconductor photodetectors are considered in relative details, and their photoelectron statistics are expressed in terms of the intrinsic material parameters.