FRACTAL CONDUCTANCE FLUCTUATIONS IN GENERIC CHAOTIC CAVITIES

It is shown that conductance fluctuations due to phase coherent ballis tic transport through a chaotic cavity generically are fractals. The g raph of conductance vs externally changed parameter, e.g., magnetic fi eld, is a fractal with dimension D = 2 - beta/2 between 1 and 2. It is governed by the exponent beta (less than or equal to 2) of the power- law distribution P(t)similar to t(-beta) for a classically chaotic tra jectory to stay in the cavity up to time t, which is typical for chaot ic systems with a mixed (chaotic and regular) phase space. The phenome non should be observable in semiconductor nanostructures and microwave billiards.