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A. I. Trubilko

Publications and source records attributed to A. I. Trubilko.

12 recordsLinked to original sources
arXiv2019

Superradiance in an external classical nonresonant field under the Stark interaction with a vacuum field

Generalized with respect to the Stark interaction of atoms with a vacuum field of zero photon density, Dicke's model is used to describe the Raman superradiance of a localized ensemble of identical atoms in a coherent non-resonant light wave. It is shown that at a certain critical number of atoms in the ensemble the stabilization effect of the excited state of the ensemble relative to collective atomic decay is possible, with superradiance of the atomic ensemble being suppressed. When the number of atoms is close to the critical value, superradiance exhibits features that are opposite to the effects of the conventional superradiance in the pulse delay time. The identified features depend on the intensity of an external coherent field as well as make it possible to assess whether the Stark interaction of an ensemble with a photon-free vacuum electromagnetic field is significant or not.

quant-ph↗
arXiv2006

Quantum channel for light based on integrals of motion

A method based on integrals of motion for collective processes has been introduced to achieve physical schemes in which one of the systems is insensitive to interaction. Decoherence-free quantum channels that allow sending any state of light, particulary the Fock states, through an absorbing medium are considered as an example.

quant-ph↗
arXiv2005

On Multiparticle Entanglement via Resonant Interaction between Light and atomic Ensembles

Multiparticle entangled states generated via interaction between narrow-band light and an ensemble of identical two-level atoms are considered. Depending on the initial photon statistics, correlation between atoms and photons can give rise to entangled states of these systems. It is found that the state of any pair of atoms interacting with weak single-mode squeezed light is inseparable and robust against decay. Optical schemes for preparing entangled states of atomic ensembles by projective measurement are described.

quant-ph↗
arXiv2004

On parametric type interaction between light and atomic ensembles

One-photon and Raman type interactions between two-level atoms and narrow-band light are considered. We give some exactly solvable models of these processes when only one-photon Fock states are involved in the evolution. Possible application of these models for generation and transformation of entangled states of the W-class, some of which demonstrate hierarchy structure, are discussed. Finally, we consider preparation of entangled chains of atomic ensembles.

quant-ph↗
arXiv2003

Can the states of the W-class be suitable for teleportation

Entangled states of the W-class are considered as a quantum channel for teleportation or the states to be sent. The protocols have been found by unitary transformation of the schemes, based on the multiuser GHZ channel. The main feature of the W-quantum channels is a set of non-local operators, that allow receivers recovering unknown state.

quant-ph↗
arXiv2003

On preparation of the W-states from atomic ensembles

A scheme, where three atomic ensembles can be prepared in the states of the W-class via Raman type interaction of strong classical field and a projection measurement involved three single-photon detectors and two beamsplitters, are considered. The obtained atomic entanglement consists of the Dicke or W-states of each of the ensembles.

quant-ph↗
arXiv2003

On amplification of light in the continuous EPR state

Two schemes of amplification of two-mode squeezed light in the continuous variable EPR-state are considered. They are based on the integrals of motion, which allow conserving quantum correlations whereas the power of each mode may increase. One of these schemes involves a three-photon parametric process in a nonlinear transparent medium and second is a Raman type interaction of light with atomic ensemble.

quant-ph↗
arXiv2002

Master Equation for Light emitted by correlated Atoms

A master equation for light generated by atoms, which states are prepared by a pumping mechanism that produces atomic correlations, is derived in the Fokker-Planck approximation. It has been found that two-particle correlations only play the role under this approach. Then the equation is applied for describing micromaser operations and light noise is discussed. We consider the correlated atomic states prepared by telecloning protocols.

quant-ph↗
arXiv2001

Teleportation of entangled states and dense coding using a multiparticle quantum channel

A set of protocols for teleportation and dense coding tasks with the use of a N particle quantum channel, presented by entangled states of the GHZ class, is introduced, when N>2. Using a found representation for the multiparticle entangled states of the GHZ class, it has shown, that for dense coding schemes enhancement of the classical capacity of the channel due from entanglement is N/N-1. If N>2 there is no one - to -one correspondence between teleportation and dense coding schemes in comparison with the EPR channel is exploited. A set of schemes, for which two additional operations as entanglement and disentanglement are permitted, is considered.

quant-ph↗
arXiv2000

Teleportation of entanglement for continuous variables

Teleportation of a pure two particle entangled state of continuous variables by triplet of the Greenberger-Horne-Zeilinger form is considered. The three-particle basis needed for a joint measurement is found. It describes a measurement of momentum one of single particle and total moment and relative position of the two others. Optical realization using squeezed state of the light is discussed.

quant-ph↗
arXiv1999

Quantum teleportation of EPR pair by three-particle entanglement

Teleportation of an EPR pair using triplet in state of the Horne-Greenberger-Zeilinger form to two receivers is considered. It needs a three-particle basis for joint measurement. By contrast the one qubit teleportation the required basis is not maximally entangled. It consists of the states corresponding to the maximally entanglement of two particles only. Using outcomes of measurement both receivers can recover an unknown EPR state however one of them can not do it separately. Teleportation of the N-particle entanglement is discussed.

quant-ph↗