Heating and decoherence suppression using decoupling techniques

We study the application of decoupling techniques to the case of a damped vibrational mode of a chain of trapped ions, which can be used as a quantum bus in linear ion trap quantum computers. We show that vibrational heating could be efficiently suppressed using appropriate ``parity kicks''. We also show that vibrational decoherence can be suppressed by this decoupling procedure, even though this is generally more difficult because the rate at which the parity kicks have to applied increases with the effective bath temperature.Comment: 13 pages, 5 figures. Typos corrected, references adde

Heisenberg-type structures of one-dimensional quantum Hamiltonians

We construct a Heisenberg-like algebra for the one dimensional infinite square-well potential in quantum mechanics. The ladder operators are realized in terms of physical operators of the system as in the harmonic oscillator algebra. These physical operators are obtained with the help of variables used in a recently developed non commutative differential calculus. This \textquotedblleft square-well algebra\textquotedblright is an example of an algebra in a large class of generalized Heisenberg algebras recently constructed. This class of algebras also contains $q$-oscillators as a particular case. We also discuss the physical content of this large class of algebras.Comment: 11 pages. The title and abstract were modified and minor corrections were made in the paper's core. Final version to appear in Phys. Rev.

XI and DELTA-non-degenerate two-photon time-dependent Jaynes-Cummings model: an exact algebraic solution

Biblioteca Centrale CNR / CNR - Consiglio Nazionale delle RichercheSIGLEITItal

Infinite set of relevant operators for an exact solution of the time-dependent Jaynes-Cummings Hamiltonian

Consiglio Nazionale delle Ricerche (CNR). Biblioteca Centrale / CNR - Consiglio Nazionale delle RichercheSIGLEITItal

Exact solution of the generalized time-dependent Jaynes-Cummings Hamiltonian

SIGLEITItal

Nonlinearity induced nontrivial dynamics in the Jaynes-Cummings Hamiltonian

Consiglio Nazionale delle Ricerche (CNR). Biblioteca Centrale / CNR - Consiglio Nazionale delle RichercheSIGLEITItal

Non-zero temperature two-mode squeezing for time-dependent two-level systems

Consiglio Nazionale delle Ricerche (CNR). Biblioteca Centrale / CNR - Consiglio Nazionale delle RichercheSIGLEITItal

Quantum dissipation is a dynamical collective effect

Consiglio Nazionale delle Ricerche (CNR). Biblioteca Centrale / CNR - Consiglio Nazionale delle RichercheSIGLEITItal