M. Martinez et Pa. Mello, Electronic transport through ballistic chaotic cavities: Reflection symmetry, direct processes, and symmetry breaking - art. no. 016205, PHYS REV E, 6302(2), 2001, pp. 6205
We extend previous studies on transport through ballistic chaotic cavities
with spatial left-right (LR) reflection symmetry to include the presence of
direct processes. We first analyze fully LR-symmetric systems in the prese
nce of direct processes and compare the distribution w(T) Of the transmissi
on coefficient T with that for an asymmetric cavity with the same ''optical
" S matrix. We then study the problem of ''external mixing" of the symmetry
caused by an asymmetric coupling of the cavity to the outside. We first co
nsider the case where symmetry breaking arises because two symmetrically po
sitioned waveguides are coupled to the cavity by means of asymmetric tunnel
barriers. Although this system is asymmetric with respect to the LR operat
ion, there is an effect of the symmetry of the cavity it was constructed fr
om. Second, we break LR symmetry in the absence of direct processes by asym
metrically positioning the two waveguides and compare the results with thos
e fur the completely asymmetric case.