0000000000306879

AUTHOR

Marcelo França Santos

showing 4 related works from this author

Vacuum induced berry phase: Theory and experimental proposal

2003

We investigate quantum effects in geometric phases arising when a two-level system is interacting with a quantized electromagnetic field. When the system is adiabatically driven along a closed loop in the parameter space, signatures of the field quantization are observable in the geometric phase. We propose a feasible experiment to measure these effects in cavity QED and also analyse the semi-classical limit, recovering the usual Berry phase results.

Electromagnetic fieldPhysicsJaynes–Cummings modelVacuumGround stateMathematical transformationObservableParameter spaceComputational geometryAtomic and Molecular Physics and OpticsClosed loop control systemQuantization (physics)Mathematical operatorGeometric phaseConvergence of numerical methodQuantum electrodynamicsQuantum mechanicsElectromagnetic fieldBerry connection and curvatureFunctionClosed loopLight polarizationJournal of Modern Optics
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Geometric phase induced by a cyclically evolving squeezed vacuum reservoir

2006

We propose a new way to generate an observable geometric phase by means of a completely incoherent phenomenon. We show how to imprint a geometric phase to a system by "adiabatically" manipulating the environment with which it interacts. As a specific scheme we analyse a multilevel atom interacting with a broad-band squeezed vacuum bosonic bath. As the squeezing parameters are smoothly changed in time along a closed loop, the ground state of the system acquires a geometric phase. We propose also a scheme to measure such geometric phase by means of a suitable polarization detection.

DECOHERENCEPhysicsQuantum PhysicsBerry phaseGeneral Physics and AstronomyFOS: Physical sciencesObservableMarkovian processPolarization (waves)Measure (mathematics)QUANTUM COMPUTATIONLIGHTClassical mechanicsGeometric phaseQuantum mechanicsAtom (measure theory)Quantum informationQuantum statistical mechanicsGround stateQuantum Physics (quant-ph)
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Coherent quantum evolution via reservoir driven holonomies.

2006

We show that in the limit of a strongly interacting environment a system initially prepared in a decoherence-free subspace (DFS) coherently evolves in time, adiabatically following the changes of the DFS. If the reservoir cyclicly evolves in time, the DFS states acquire a holonomy.

PhysicsQuantum decoherenceHolonomyGeneral Physics and AstronomyComputer Science::Software EngineeringQuantum evolutionComputer Science::PerformanceQuantum mechanicsHolonomieLimit (mathematics)Decoherence-free subspace (DFS)Quantum evolutionComputer Science::Data Structures and AlgorithmsSubspace topologyPhysical review letters
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Anyons and transmutation of statistics via vacuum induced Berry phase

2004

We show that bosonic fields may present anyonic behavior when interacting with a fermion in a Jaynes-Cummings-like model. The proposal is accomplished via the interaction of a two-level system with two quantized modes of a harmonic oscillator; under suitable conditions, the system acquires a fractional geometric phase. A crucial role is played by the entanglement of the system eigenstates, which provides a two-dimensional confinement in the effective evolution of the system, leading to the anyonic behavior. For a particular choice of parameters, we show that it is possible to transmute the statistics of the system continually from fermions to bosons. We also present an experimental proposal…

PhysicsCondensed Matter::Quantum GasesQuantum PhysicsNuclear transmutationFOS: Physical sciencesQuantum PhysicsFermionQuantum entanglementTopological quantum computerAtomic and Molecular Physics and OpticsBosonic excitationHigh Energy Physics::TheoryGeometric phaseQuantum mechanicsStatisticsAnyonQuantum Physics (quant-ph)Harmonic oscillatorEigenvalues and eigenvectorsBoson
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