MAGNETOCONDUCTANCE IN OPEN BILLIARDS - COMPARISON BETWEEN CIRCLE AND STADIUM

A comparative study is presented on quantum transports in weakly opene d circle and stadium billiards in the perpendicular magnetic field B. While in the circle the magnetoconductance g(B) shows grossly regular oscillations, in the stadium it exhibits a transition from mild to vio let undulations with increase of B. The rich fluctuation features of g (B), characterized by gradients of the cusp-like central peaks in auto correlation functions, are attributed to the stability and instability of phase space in the underlying classical dynamics.