Valerio Cappellini

Random Quantum Operations (2008)

Bruzda, Wojciech, Cappellini, Valerio, Sommers, Hans-Jürgen, Zyczkowski, Karol \.

We define a natural ensemble of trace preserving, completely positive quantum maps and present algorithms to generate them at random. Spectral properties of the superoperator Phi associated with a...

A Survey on the Classical Limit of Quantum Dynamical Entropies (2007)

Cappellini, Valerio

We analyze the behavior of quantum dynamical entropies production from sequences of quantum approximants approaching their (chaotic) classical limit. The model of the quantized hyperbolic...

Subnormalized states and trace-nonincreasing maps (2007)

Cappellini, Valerio, Sommers, Hans-Juergen, Zyczkowski, Karol

We investigate the set of completely positive, trace-nonincreasing linear maps acting on the set M_N of mixed quantum states of size N. Extremal point of this set of maps are characterized and its...

Distribution of G-concurrence of random pure states (2006)

Cappellini, Valerio, Sommers, Hans-Juergen, Zyczkowski, Karol

Average entanglement of random pure states of an N x N composite system is analyzed. We compute the average value of the determinant D of the reduced state, which forms an entanglement monotone....

Quantum dynamical entropies for discrete classical systems: a comparison (2005)

Cappellini, Valerio

On a family of classical dynamical systems on the 2-torus, we perform a discretization procedure similar to the Anti-Wick quantization. Such a discretization is performed by using a particular class...

Continuous Limit of Discrete Sawtooth Maps and its Algebraic Framework (2004)

Benatti, Fabio, Cappellini, Valerio

We study the presence of a logarithmic time scale in discrete approximations of Sawtooth Maps on the 2--torus. The techniques used are suggested by quantum mechanical similarities, and are based on a...

Quantum Dynamical Entropies and Complexity in Dynamical Systems (2004)

Cappellini, Valerio

We analyze the behaviour of two quantum dynamical entropies in connection with the classical limit. Using strongly chaotic classical dynamical systems as models (Arnold Cat Maps and Sawtooth Maps),...