arXiv subjects

M. Amniat-Talab

Publications and source records attributed to M. Amniat-Talab.

6 recordsLinked to original sources

arXiv2020

Effects of partial measurements on quantum resources and quantum Fisher information of a teleported state in a relativistic scenario

We address the teleportation of single- and two-qubit quantum states, parametrized by weight $θ$ and phase $ϕ$ parameters, in the presence of the Unruh effect experienced by a mode of a free Dirac field. We investigate the effects of the partial measurement (PM) and partial measurement reversal (PMR) on the quantum resources (QRs) and quantum Fisher information (QFI) of the teleported states. In particular, we discuss the optimal behavior of the QFI, quantum coherence (QC) as well as fidelity with respect to the PM and PMR strength and examine the effect of the Unruh noise on optimal estimation. It is found that in the single-qubit scenario, the PM (PMR) strength at which the optimal estimation of the phase parameter occurs, is the same as the PM (PMR) strength with which the teleportation fidelity and the QC of the teleported single-qubit state reaches to its maximum value. On the other hand, generalizing the results to two-qubit teleportation, we find that the encoded information in the weight parameter is better protected against the Unruh noise in two-qubit teleportation than the one-qubit scenario. However, extraction of information encoded in the phase parameter is more efficient in single-qubit teleportation than the two-qubit one.

quant-ph↗

arXiv2009

Robust creation of atomic W state in a cavity by adiabatic passage

We propose two robust schemes to generate controllable (deterministic) atomic W-states of three three-level atoms interacting with an optical cavity and a laser beam. Losses due to atomic spontaneous emissions and to cavity decay are efficiently suppressed by employing adiabatic passage technique and appropriately designed atom-field couplings. In these schemes the three atoms traverse the cavity-mode and the laser beam and become entangled in the free space outside the cavity.

quant-ph↗

arXiv2006

Quantum state engineering in a cavity by Stark chirped rapid adiabatic passage

We propose a robust scheme to generate single-photon Fock states and atom-photon and atom-atom entanglement in atom-cavity systems. We also present a scheme for quantum networking between two cavity nodes using an atomic channel. The mechanism is based on Stark-chirped rapid adiabatic passage (SCRAP) and half-SCRAP processes in a microwave cavity. The engineering of these states depends on the design of the adiabatic dynamics through the static and dynamic Stark shifts.

quant-ph↗

arXiv2004

Atom-photon, atom-atom and photon-photon entanglement preparation via fractional adiabatic passage

We propose a relatively robust scheme to generate maximally entangled states of (i) an atom and a cavity photon, (ii) two atoms in their ground states, and (iii) two photons in two spatially separate high-Q cavities. It is based on the interaction via fractional adiabatic passage of a three-level atom traveling through a cavity mode and a laser beam. The presence of optical phases is emphasized.

quant-ph↗

arXiv2004

Generation of multi-photon Fock states by bichromatic adiabatic passage: topological analysis

We propose a robust scheme to generate multi-photon Fock states in an atom-maser-cavity system using adiabatic passage techniques and topological properties of the dressed eigenenergy surfaces. The mechanism is an exchange of photons from the maser field into the initially empty cavity by bichromatic adiabatic passage. The number of exchanged photons depends on the design of the adiabatic dynamics through and around the conical intersections of dressed eigenenergy surfaces.

quant-ph↗

arXiv2003

Quantum averaging and resonances: two-level atom in a one-mode quantized field

We construct a non-perturbative approach based on quantum averaging combined with resonant transformations to detect the resonances of a given Hamiltonian and to treat them. This approach, that generalizes the rotating-wave approximation, takes into account the resonances at low field and also at high field (non-linear resonances). This allows to derive effective Hamiltonians that contain the qualitative features of the spectrum, i.e. crossings and avoided crossings, as a function of the coupling constant. At a second stage the precision of the spectrum can be improved quantitatively by standard perturbative methods like contact transformations. We illustrate this method to determine the spectrum of a two-level atom interacting with a single mode of a quantized field.

quant-ph↗