Quantum correlations and coherence in a driven two-qubit system under non-Markovian dissipative effect

Highlights: • Qubit systems including classical driving field. • Time-dependent effect on the comportments of the quantum quantifiers in quantum technologies. • Markovian and non-Markovian dynamics. • Quantum coherence dynamics. • Dynamics of classical and quantum correlations • Effect of pure and mixed states. Abstract: By considering an exactly solvable model for a driven two non-interacting qubits, each coupled to a bosonic environment with zero temperature, under the non-Markovian dissipative process, we study the variation of coherence and correlations in terms of different physical parameters. We show the influence of the external classical driving field as well as the initial quantum states. Moreover, we highlight the relationship between the coherence, single-qubit population, and correlations according to the physical parameters of the whole system. We reveal that the preservation and enhancement of coherence and correlations may occur by adjusting the strength of the classical driving field, initial states, and non-Markovian effects

Interaction of a three-level atom and a field with a time-varying frequency in the context of triangular well potentials: an exact treatment

We introduce a model of interaction between a three-level atom (3LA) and a one-mode field whose frequency evolves with the time in the context of triangular potentials. We consider a new class of cat states described as a superposition of the coherent states that are associated with these kinds of potentials. Mathematical and physical consequences of the obtained results are analyzed and discussed in detail by using the exact analytical treatment of the quantum system-state at subsequent times. We investigate the nonlocal and nonclassical properties of different system states in terms of the main parameters of the model. Interestingly, we present the dynamical behavior of the entanglement, second order correlation function, quantum Fisher information, and geometric phase of the considered bipartite quantum system. We show that the physical quantities for the proposed scheme are very sensitive through the choice of the time-varying frequency of the fields, at either coherent states or their superposition, and we compare the results to the case of fields that are associated to harmonic well potentials. Finally, we explore the relationship and dependence of the physical quantifiers on the main parameters of the model

Quantum correlations and quantum fisher information of two qubits in the presence of the time-dependent coupling effect

In this paper, we consider two separate Jaynes–Cummings (JC) nodes with a nonidentical qubit-field system in the presence of dissipation terms. We reveal the influence of the time variation of the coupling terms on some important measures when the qubits are immersed in a vacuum. The density matrix for the two qubits initially in Bell states are obtained. The dynamical behavior of the quantum discord (QD), classical correlation (CC), qubit-qubit entanglement, and quantum Fisher information (QFI) is investigated. We explore the relationship among QD, CC, qubit-qubit entanglement, and QFI in the absence and presence of the dissipation effect during the time evolution. Furthermore, we show the main optimal conditions for obtaining a high level of correlation and coherence between the two qubits. © 2020, Società Italiana di Fisica and Springer-Verlag GmbH Germany, part of Springer Nature

Quantum Quantifiers for an Atom System Interacting with a Quantum Field Based on Pseudoharmonic Oscillator States

We develop a useful model considering an atom-field system interaction in the framework of pseudoharmonic oscillators. We examine qualitatively the different physical quantities for a two-level atom (TLA) system interacting with a quantized coherent field in the context of photon-added coherent states of pseudoharmonic oscillators. Using these coherent states, we solve the model that exhibits the interaction between the TLA and field associated with these kinds of potentials. We analyze the temporal evolution of the entanglement, statistical properties, geometric phase and squeezing entropies. Finally, we show the relationship between the physical quantities and their dynamics in terms of the physical parameters

Influence of Xenon–Fluorine–Sulfur Hexafluoride (<i>Xe</i>⁺–<i>F</i>⁻–<i>SF</i>6⁻) and Argon-Fluorine-Sulfur Hexafluoride (<i>Ar</i>⁺–<i>F</i>⁻–<i>SF</i>6⁻) Streaming on Dust Surface Potential (DSP) That Has Cairn–Tsallis Distributed Plasmas

The dust grain surface potential is examined analytically and numerically in dusty plasmas containing negative/positive ion species by using the Cairn Tsallis (non-Maxwellian) dusty plasma. The equations for the dust-charging process are derived to solve the current balance equation for the xenon–fluorine–sulfur hexafluoride and argon–fluorine–sulfur hexafluoride plasmas. The charging process affected by plasma properties such as spectral indices α and q, in addition to positive ion streaming (UAr+ and UXe+) and negative ion streaming (UF− and USF6−) of both types of plasmas, is examined. Our findings suggest that considering a wide range of Xe+−F−−SF6− and Ar+−F−−SF6− masses is critical for understanding plasma physics, specifically multi-component plasmas

Realistic Quantum Control of Energy Transfer in Photosynthetic Processes

The occurrence of coherence phenomenon as a result of the interference of the probability amplitude terms is among the principle features of quantum mechanics concepts. Current experiments display the presence of quantum techniques whose coherence is supplied over large interval times. Specifically, photosynthetic mechanisms in light-harvesting complexes furnish oscillatory behaviors owing to quantum coherence. In this manuscript, we study the coherent quantum energy transfer for a single-excitation and nonlocal correlation in a dimer system (donor+acceptor) displayed by two-level systems (TLSs), interacting with a cavity field with a time-dependent coupling effect considering the realistic situation of coupling between each TLS and the cavity field. We analyze and explore the specific conditions which are viable with real experimental realization for the ultimate transfer of quantum energy and nonlocal quantum correlation. We show that the enhancement of the probability for a single-excitation energy transfer greatly benefits from the energy detuning, photon-number transition, classicality of the field, and the time-dependent coupling effect. We also find that the entanglement between the donor and acceptor is very sensitive to the physical parameters and it can be generated during the coherent energy transfer

Information quantifiers for trapped ion in a carrier excitation laser field

The laser field interacting with single trapped ion in a carrier excitation frame in the presence of an external field is investigated. Detailed analytical expressions are given, taking into account carrier excitation configurations. We study the evolution of the population inversion, fidelity, ion-field entanglement, Fisher information and the geometric phase. The results indicate the influence of the external field on the information quantities to describe some physical phenomena. The relation between the population inversion, fidelity, von Neumann entropy, Fisher information, and geometric phase are explored during the time evolution

Quantum transfer energy in the framework of time-dependent dipole-dipole interaction

In this work, we examine the process of the quantum transfer of energy considering time-dependent dipole-dipole interaction in a dimer system characterized by two-level atom systems. By taking into account the effect of the acceleration and speed of the atoms in the dimer coupling, we demonstrate that the improvement of the probability for a single-excitation transfer energy extremely benefits from the incorporation of atomic motion effectiveness and the energy detuning. We explore the relevance between the population and entanglement during the time-evolution and show that this kind of nonlocal correlation may be generated during the process of the transfer of energy. Our work may provide optimal conditions to implement realistic experimental scenario in the transfer of the quantum energy. Keywords: Quantum energy transfer, Quantum acceleration and speed, Dipole-dipole interaction, Population, Dimer system, Two-level atom system, Quantum correlation