We show how the interference between spatially separated states of center mass (c.m.) a mesoscopic harmonic oscillator can be evidenced by coupling it to spin and performing solely manipulations measurements (Ramsey interferometry). propose use an optically levitated diamond bead containing nitrogen-vacancy spin. The nanoscale size makes motional decoherence due levitation negligible. form spin-motion ensures that scheme works for thermal so moderate feedback cooling suffices. No separate...

We propose an interferometric scheme based on untrapped nano-object subjected to gravity. The motion of the center mass (c.m.) free object is coupled its internal spin system magnetically, and a flight developed coherent control. wave packet test object, under spin-dependent force, may then be delocalized macroscopic scale. A gravity induced dynamical phase (accrued solely state, measured through Ramsey scheme) used reveal above spatially superposition spin-nano-object composite that arises...

In this paper we provide a microscopic derivation of the master equation for Jaynes-Cummings model with cavity losses. We single out both differences phenomenological used in literature and approximations under which correctly describes dynamics atom-cavity system. Some examples wherein equations give rise to different predictions are discussed detail.

The reduced dynamics of two interacting qubits coupled to independent bosonic baths is investigated. one-excitation derived and compared with that based on the resolution appropriate non-Markovian master equations. Nakajima-Zwanzig time-convolutionless projection operator techniques are exploited provide a description features two-qubit system. validity such approximate methods their range in correspondence different choices parameters describing system brought light.

A master equation approach to the study of environmental effects in adiabatic population transfer three-state systems is presented. systematic comparison with non-Hermitian Hamiltonian [Vitanov and Stenholm, Phys. Rev. 56, 1463 (1997)] shows that, weak-coupling limit, two treatments lead essentially same results. In contrast, strong-damping limit predictions are quite different: particular, counterintuitive sequences STIRAP scheme turn out be much more efficient than expected before. This...

A microscopic derivation of the master equation for Jaynes-Cummings model with cavity losses is given, taking into account terms in dissipator which vary frequencies order vacuum Rabi frequency. Our approach allows to single out physical contexts wherein usual phenomenological turns be fully justified and constitutes an extension our previous analysis [Scala M. {\em et al.} 2007 Phys. Rev. {\bf 75}, 013811], where a was given framework Rotating Wave Approximation.

We derive the master equation of a system two coupled qubits by taking into account their interaction with independent bosonic baths.Important features dynamics are brought to light, such as structure stationary state at general temperatures and behaviour entanglement zero temperature, showing phenomena sudden death birth well presence for long times.The model here presented is quite versatile can be interest in study both Josephson junction architectures cavity-QED.

In population trapping the occupation of a decaying quantum level keeps constant nonzero value. We show that an atom-cavity system interacting with environment characterized by nonflat spectrum, in non-Markovian limit, exhibits such behavior, effectively realizing preservation nonclassical states against dissipation. Our results allow us to understand role cavity losses hybrid solid state systems and pave way proper description leakage recently developed electrodynamic systems.

We exploit a microscopically derived master equation for the study of STIRAP in presence decay from auxiliary level toward initial and final state, compare our results with predictions obtained phenomenological model previously used [P. A. Ivanov, N. V. Vitanov, K. Bergmann, Phys. Rev. A 72, 053412 (2005)]. It is shown that approach predicts much higher efficiency. The effects temperature are also taken into account, proving b-STIRAP thermal pumping can increase efficiency population transfer.

We discuss the partitioning of Hilbert space a quantum system induced by interaction with another at thermal equilibrium, showing that higher temperature more effective is formation Zeno subspaces. show our analysis keeps its validity even in case bosonic reservoir, provided appropriate limitations relevant bandwidth.

We analyze the effect of a dissipative bosonic environment on Landau-Zener-St\"uckelberg-Majorana (LZSM) level crossing model by using microscopic approach to derive relevant master equation. For an at zero temperature and weak dissipation, our confirms independence survival probability decay rate that has been predicted earlier simple phenomenological LZSM model. strong predicts notable increase probability, which signals dynamical decoupling initial state. Unlike model, makes it possible...

In the scheme recently proposed by M. Scala et al. [Phys. Rev. Lett. 111, 180403 (2013)], a gravity-dependent phase shift is induced on spin of nitrogen-vacancy (NV) center in trapped nanodiamond interaction between its magnetic moment and quantized motion particle. This provides way to detect spatial quantum superpositions means only measurements. Here, effect unwanted coupling with other motional degrees freedom considered, we show that it does not affect validity scheme. Both this...

The presence of a continuous measurement quantum Zeno effect in stimulated Raman adiabatic passage is studied, exploring detail sort self-competition the damping, which drives system toward loss population and, at same time, realizes conditions for optimizing passage.

The dynamics of an open quantum system, consisting three superconducting qubits interacting with independent reservoirs, is investigated to elucidate the effects environment on a unitary generation scheme W states (Migliore R et al 2006 Phys. Rev. B 74 104503). To this end microscopic master equation constructed and its exact resolution predicts Werner-like state instead state. A comparison between our model more intuitive phenomenological also considered, in order find limits latter...

We analyze an entangling protocol to generate tripartite Greenberger-Horne-Zeilinger states in a system consisting of three superconducting qubits with pairwise coupling.The dynamics the open quantum is investigated by taking into account interaction each qubit independent bosonic bath ohmic spectral structure.To this end microscopic master equation constructed and exactly solved.We find that here discussed stable against decoherence dissipation due presence external baths.

In the framework of dissipative dynamics coupled qubits interacting with independent reservoirs, a comparison between non-Markovian master equation techniques and an exact solution is presented here.We study various regimes in order to find limits validity Nakajima-Zwanzig time-convolutionless equations description entanglement dynamics.A performances concurrence negativity as measures for system under also presented.

Understanding the relationships between onset of volcanic eruptions and external forcings, such as solid Earth ocean tides, can help us to understand underlying dynamics processes have implications for monitoring prediction efforts.Many studies that explored relationship tidal forces activity shown certain phases cycles are associated with an increased likelihood eruptions. At longer-time scales hundreds thousands years, pronounced sea level variations related ice melting or climatic...

We investigate the role of anisotropy in dynamics a single trapped ion interacting with two orthogonal laser beams, considering how it modifies scheme for generation Schrödinger cat states and so called parity effect two-dimensional isotropic Paul traps. find that gives rise to richer class generated larger number observables sensitive excitation vibrational motion ion.

Complete positivity of a class maps generated by master equations derived beyond the secular approximation is discussed.The connection between such evolutions and physical properties system analyzed in depth.It also shown that under suitable hypotheses Zeno dynamics can be induced because high temperature bath.

We derive the master equation of a system two coupled state systems by taking into account their interaction with independent bosonic baths [1]. Important features dynamics are brought to light, such as stationary at general temperatures and behaviour entanglement zero temperature, presenting phenomena sudden death birth well presence for long times. The model presented is quite versatile exploited in analysis Josephson junction based architecture [2].