6533b859fe1ef96bd12b7978

RESEARCH PRODUCT

Relaxation due to random collisions with a many-qudit environment

Giuliano BenentiGiuliano BenentiG. GennaroG. Massimo Palma

subject

PhysicsQuantum PhysicsQuantum decoherenceMarkov chainFOS: Physical sciencesQuantum entanglementQuantum PhysicsUnitary transformationEffective dimensionMultipartite entanglementAtomic and Molecular Physics and OpticsQuantum mechanicsQubitfondamental conceptsRelaxation (approximation)Quantum Physics (quant-ph)

description

We analyze the dynamics of a system qudit of dimension mu sequentially interacting with the nu-dimensional qudits of a chain playing the ore of an environment. Each pairwise collision has been modeled as a random unitary transformation. The relaxation to equilibrium of the purity of the system qudit, averaged over random collisions, is analytically computed by means of a Markov chain approach. In particular, we show that the steady state is the one corresponding to the steady state for random collisions with a single environment qudit of effective dimension nu_e=nu*mu. Finally, we numerically investigate aspects of the entanglement dynamics for qubits (mu=nu=2) and show that random unitary collisions can create multipartite entanglement between the system qudit and the qudits of the chain.

10.1103/physreva.79.022105http://hdl.handle.net/10447/36704