Density matrix of chaotic quantum systems

Open Quantum Systems: Density Matrix Formalism and Applications

Dynamics of quantum trajectories in chaotic systems

– Quantum trajectories defined in the de Broglie–Bohm theory provide a causal way to interpret physical phenomena. In this Letter, we use this formalism to analyze the short time dynamics induced by unstable periodic orbits in a classically chaotic system, a situation in which scars are known to play a very important role. We find that the topologies of the quantum orbits are much more complica...

Exponentially Rapid Decoherence of Quantum Chaotic Systems

We use a recent result to show that the rate of loss of coherence of a quantum system increases with increasing system phase-space structure and that a chaotic quantal system in the semiclassical limit decoheres exponentially with rate 2l2, where l2 is a generalized Lyapunov exponent. As a result, for example, the dephasing time for classically chaotic systems goes to infinity logarithmically w...

Quantum response of weakly chaotic systems

Chaotic systems, that have a small Lyapunov exponent, do not obey the common random matrix theory predictions within a wide “weak quantum chaos” regime. This leads to a novel prediction for the rate of heating for cold atoms in optical billiards with vibrating walls. The Hamiltonian matrix of the driven system does not look like one from a Gaussian ensemble, but rather it is very sparse. This s...

Orbital magnetism of classically chaotic quantum systems

– We employ orbital magnetic response functions as a tool to investigate fluxdependent 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 thre...