0000000000717297
AUTHOR
R Migliore
Dissipative effects on a scheme of generation of a W state in an array of coupled Josephson junctions
The dynamics of an open quantum system, consisting of three superconducting qubits interacting with independent reservoirs, is investigated to elucidate the effects of the environment on a unitary generation scheme of W states (Migliore R et al 2006 Phys. Rev. B 74 104503). To this end a microscopic master equation is constructed and its exact resolution predicts the generation of a Werner-like state instead of the W state. A comparison between our model and a more intuitive phenomenological model is also considered, in order to find the limits of the latter approach in the case of structured reservoirs.
Selective reset of a chain of interacting superconducting qubits
We propose and analyze a scheme for the selective reset of a chain of inductively coupled Josephson flux qubits initially prepared in a multipartite entangled state. The possibility of controlling at will the coupling between two prefixed qubits is exploited to drive a "generalized W state" to a factorized state with only one qubit in the excited state and all the other qubits in their own ground states.
Nonclassical correlations in superconducting circuits
A key step on the road map to solid-state quantum information processing (and to a deeper understanding of many counterintuitive aspects of quantum mechanics) is the generation and manipulation of nonclassical correlations between different quantum systems. Within this framework, we analyze the possibility of generating maximally entangled states in a system of two superconducting flux qubits, as well as the effect of their own environments on the entanglement dynamics. The analysis reported here confirms that the phenomena of sudden birth and sudden death of the entanglement do not depend on the particular measure of the entanglement adopted.
CONTROLLING THE QUANTUM DYNAMICS OF MULTIPARTITE JOSEPHSON CIRCUITS
CONTROLLING THE QUANTUM DYNAMICS OF MULTIPARTITE JOSEPHSON CIRCUITS