Europhys. Lett, 41 (6), pp. 587-592 (1998)
Orbital magnetism of classically chaotic quantum systems
K. Richter and B. Mehlig
Max-Planck-Institut für Physik komplexer Systeme
Nöthnitzer Str. 38, 01187 Dresden, Germany
(received 4 July 1997; accepted in final form 29 January 1998)
PACS. 03.65Sq - Semiclassical theories and
PACS. 73.20Dx - Electron states in low-dimensional structures (superlattices, quantum well structures and multilayers).
We employ orbital magnetic response functions as a tool to investigate flux-dependent spectral correlations of chaotic quantum dots in the ballistic regime. We compare for the first time results for the persistent current and susceptibility from a semiclassical theory (without adjustable parameters) with accurate quantum-mechanical calculations for the case of an ensemble of chaotic rings threaded by a magnetic flux. We discuss the temperature dependence and suggest this to be a natural and physically relevant parameter in order to study (experimentally) the signature of different semiclassical timescales in smoothed spectral correlation functions.