Universal Quantum Signatures of Chaos in Ballistic Transport

Abstract

The conductance of a ballistic quantum dot (having chaotic classical dynamics\nand being coupled by ballistic point contacts to two electron reservoirs) is\ncomputed on the single assumption that its scattering matrix is a member of\nDyson's circular ensemble. General formulas are obtained for the mean and\nvariance of transport properties in the orthogonal (beta=1), unitary (beta=2),\nand symplectic (beta=4) symmetry class. Applications include universal\nconductance fluctuations, weak localization, sub-Poissonian shot noise, and\nnormal-metal-superconductor junctions. The complete distribution P(g) of the\nconductance g is computed for the case that the coupling to the reservoirs\noccurs via two quantum point contacts with a single transmitted channel. The\nresult P(g)=g^(-1+beta/2) is qualitatively different in the three symmetry\nclasses. ***Submitted to Europhysics Letters.****\n