Search results for " open systems"

showing 3 items of 3 documents

Entanglement dynamics in superconducting qubits affected by local bistable impurities

2012

We study the entanglement dynamics for two independent superconducting qubits each affected by a bistable impurity generating random telegraph noise (RTN) at pure dephasing. The relevant parameter is the ratio $g$ between qubit-RTN coupling strength and RTN switching rate, that captures the physics of the crossover between Markovian and non-Markovian features of the dynamics. For identical qubit-RTN subsystems, a threshold value $g_\mathrm{th}$ of the crossover parameter separates exponential decay and onset of revivals; different qualitative behaviors also show up by changing the initial conditions of the RTN. We moreover show that, for different qubit-RTN subsystems, when both qubits are …

BistabilityDephasingCrossoverquantum statistical methodEntanglement measures witnesses and other characterizations Decoherence; open systems; quantum statistical methods; Quantum computation architectures and implementationsFOS: Physical sciencesQuantum computation architectures and implementationsQuantum entanglement01 natural sciencesNoise (electronics)Settore FIS/03 - Fisica Della Materia010305 fluids & plasmasComputer Science::Emerging TechnologiesQuantum mechanics0103 physical sciencesExponential decay010306 general physicsMathematical PhysicsEntanglement measures witnesses and other characterizations DecoherencePhysicsQuantum PhysicsQuantum PhysicsCondensed Matter PhysicsAtomic and Molecular Physics and OpticsAmplitudeQubitopen systemQuantum Physics (quant-ph)
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Cold-Atom-Induced Control of an Optomechanical Device

2010

We consider a cavity with a vibrating end mirror and coupled to a Bose-Einstein condensate. The cavity field mediates the interplay between mirror and collective oscillations of the atomic density. We study the implications of this dynamics and the possibility of an indirect diagnostic. Our predictions can be observed in a realistic setup that is central to the current quest for mesoscopic quantumness.

Field (physics)General Physics and AstronomyFOS: Physical sciencesQuantum entanglementPhysics and Astronomy(all)01 natural sciences010305 fluids & plasmaslaw.invention/dk/atira/pure/subjectarea/asjc/3100lawUltracold atomQuantum mechanics0103 physical sciencesCold Atoms nanodevices entanglement open systemsQuantum information010306 general physicsPhysicsCondensed Matter::Quantum GasesMesoscopic physicsQuantum PhysicsCavity quantum electrodynamicsNonlinear opticsQuantum Gases (cond-mat.quant-gas)Physics::Accelerator PhysicsAtomic physicsCondensed Matter - Quantum GasesQuantum Physics (quant-ph)Bose–Einstein condensate
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Dynamics of a quantum particle interacting with a thermal bath and subject to an oscillating asymmetric bistable potential

2012

Exploiting the approach of the Feynman-Vernon influence functional [1] within the framework of the discrete variable representation (DVR) [2], we consider a quantum particle described by the Caldeira-Leggett model [3]. The particle, “moving” in an asymmetric bistable potential and subject to a periodical driving, interacts with a thermal bath of harmonic oscillators. In this conditions we study the dynamics of the particle by analyzing the time evolution of the populations in the DVR. Specifically we focalize on the position eigenstate located in the shallower well, i.e. metastable state, finding a non-monotonic behaviour of the corresponding population as a function of the frequency. Moreo…

Quantum systems with finite Hilbert spaceFluctuation phenomena random processes noise and Brownian motionquantum statistical methodDecoherenceopen systemQuantum systems with finite Hilbert space;Decoherence; open systems; quantum statistical methods;Fluctuation phenomena random processes noise and Brownian motionSettore FIS/03 - Fisica Della Materia
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