Browsing by Author "LEE, YC"

Now showing 1 - 7 of 7

A HEURISTIC APPROACH TO MULTI-MODE THEORY OF SUPERCONDUCTIVITY AND THE EFFECT OF MODE-DAMPING
(1989)
LEE, YC
;
MENDOZA, B
;
CHUU, DS
;
電子物理學系
;
Department of Electrophysics
FINDING THE MOST VITAL EDGE WITH RESPECT TO MINIMUM SPANNING TREE IN WEIGHTED GRAPHS
(1991-09-13)
HSU, LH
;
JAN, RH
;
LEE, YC
;
HUNG, CN
;
CHERN, MS
MULTIPLE BRANCHES OF ACOUSTIC PLASMA-OSCILLATIONS IN THIN WIRES
(1983)
LEE, YC
;
ULLOA, SE
;
LEE, PS
;
電子物理學系
;
Department of Electrophysics
NONVARIATIONAL APPROACH TO IMPURITY STATES IN QUANTUM WIRES
(1994-11-15)
JAN, JF
;
LEE, YC
;
CHUU, DS
;
電子物理學系
;
Department of Electrophysics
RENORMALIZED FREQUENCY-SHIFT OF SUPERRADIANT EXCITONS IN THIN SEMICONDUCTOR-FILMS
(1992-08-17)
LEE, YC
;
CHUU, DS
;
MEI, WN
;
電子物理學系
;
Department of Electrophysics
The radiative frequency shift of an exciton in a thin semiconductor film, like its radiative level width, is shown to be superradiatively enhanced. Unlike the latter, however, a finite frequency shift can only be obtained after proper renormalization for the correlated system. The shift is found to be inversely proportional to the square of the factor k0d and proportional to the film thickness T; k0 = E(qn)/H(BAR)c, E(qn) being the exciton energy gap and d the lattice constant of the semiconductor. Therefore, the coherent frequency shift can be observed experimentally if one varies the thickness, or the exciton energy gap E(qn) by imposing high pressure.
STUDIES OF ELECTRON-HYDROGEN ATOM COLLISION BY EIKONAL APPROXIMATION
(1994-10-01)
CHUU, DS
;
HUNG, HC
;
LEE, YC
;
物理研究所
;
Institute of Physics
The eikonal approximation is applied to study the elastic and inelastic scattering of an electron by the hydrogen atom. The trajectory of the incident electron is assumed as a hyperbolic curve. 1s - 1s, 1s - 2s and 1s - 2p differential cross sections at various incident electron energies are calculated and compared with the previous works. Our calculated differential cross sections agree better with the corresponding observed values than those obtained by the first order Born approximation and straight line or angle eikonal approximations, especially in the larger scattering angle region. It is also found that the exchange effect for the incident and the atomic electrons becomes important as the incident energy is below similar to 50 eVs. The including of the exchange effect at low energy indeed improves the calculated results. It is found that hyperbolic eikonal approximation is superior to the straight line or angle eikonal approximation in the incident electron energy range of 50 similar to 200 eVs.
THE KINETIC-ENERGY DENSITY FUNCTIONAL FOR FAST-VARYING DENSITIES
(1988-05-30)
LEE, YC
;
CHUU, DS
;
電子物理學系
;
Department of Electrophysics