Effect of the time-dependent coupling on a superconducting qubit-field system under decoherence: Entanglement and Wehrl entropy

2015 ◽  
Vol 361 ◽  
pp. 247-258 ◽  
Author(s):  
S. Abdel-Khalek ◽  
K. Berrada ◽  
H. Eleuch
Keyword(s):  
Time Dependent ◽  
Superconducting Qubit ◽  
Wehrl Entropy ◽  
Field System

WEHRL ENTROPY AND ENTANGLEMENT OF A TIME-DEPENDENT TWO-LEVEL TRAPPED ION INTERACTING WITH A LASER FIELD

2008 ◽  
Vol 06 (02) ◽  
pp. 331-339
Author(s):  
MAHMOUD ABDEL-ATY ◽  
SAYED ABDEL-KHALEK ◽  
ABDEL-SHAFY F. OBADA
Keyword(s):  
Exact Solution ◽  
Time Evolution ◽  
Laser Field ◽  
Equation Of Motion ◽  
Time Dependent ◽  
Heisenberg Equation ◽  
Wehrl Entropy ◽  
Entanglement Generation ◽  
Trapped Ion ◽  
Cat States

The time evolution of the atomic Wehrl entropy and long-lived entanglement generation using a single trapped ion interacting with a laser field are analyzed. Starting from the Heisenberg equation of motion, an exact solution of the system is obtained by indicating that there are some interesting features when a time-dependent modulating function is considered. We demonstrate that the long-living quantum entanglement can be obtained using the time-independent interaction when the field is initially in a pair cat states.

Geometric Phase of Time-Dependent Superconducting Qubit

2014 ◽  
Vol 54 (5) ◽  
pp. 1617-1626 ◽  
Author(s):  
G. R. Zeng ◽  
Yanyan Jiang ◽  
Z. Q. Chen ◽  
Yanxia Yu
Keyword(s):  
Geometric Phase ◽  
Time Dependent ◽  
Superconducting Qubit

JAYNES-CUMMINGS MODEL AS A CASE STUDY FOR THE DERIVATION OF TIME-DEPENDENT SCHRÖDINGER EQUATION

2008 ◽  
Vol 22 (25n26) ◽  
pp. 4557-4564
Author(s):  
SUPITCH KHEMMANI ◽  
VIRULH SA-YAKANIT
Keyword(s):  
Schrödinger Equation ◽  
Coherent State ◽  
Linear Combination ◽  
Schrodinger Equation ◽  
Time Dependent ◽  
State Representation ◽  
Field System ◽  
Single State ◽  
Special Case

The derivation of a time-dependent Schrödinger equation (TDSE) from a time-independent Schrödinger equation (TISE) in the coherent state representation is considered for the special case of a simple coupled atom-field system described by the soluble Jaynes-Cummings model. The derivation shows why, from the outset, a linear combination of energy eigenstates, instead of a single state, must be used in order to obtain a TDSE for general states. Moreover, this study leads to a method of solving a TDSE by simply solving a TISE.

scholarly journals Nonclassical Atomic System Dynamics Time-dependently Interacts With Finite Entangled Pair Coherent Parametric Converter Cavity Fields

2021 ◽  
Author(s):  
A.B. mohamed ◽  
E. M. Khalil ◽  
M. Y. Abd-Rabbou
Keyword(s):  
Phase Space ◽  
Time Dependent ◽  
Physical Parameters ◽  
Atomic Coherence ◽  
Wehrl Entropy ◽  
Location Parameters ◽  
Parametric Converter ◽  
Dependent Model ◽  
The Difference ◽  
Quantum Phenomena

Abstract We consider a time-dependent model that describes a qubit time-dependently interacts with a cavity containing finite entangled pair coherent parametric converter fields. The dynamics of some quantum phenomena, as: phase space information, quantum entanglement and squeezing, are explored by atomic Husimi function, atomic Wehrl entropy, variance, and entropy squeezing. The influences of the unitary qubit-cavity interaction, the difference between the two-mode photon numbers, the initial atomic coherence, and the time-dependent qubit location are investigated. It is found that the regularity, the amplitudes and the frequency of the quantum phenomena can be controlled by the physical parameters. For the initial atomic pure state, the qubit-cavity entanglement, the qubit phase space information, and atomic squeezing can be generated strongly compared to those of the initial atomic mixed state. The time-dependent location parameters enhance the generated quantum phenomena, and its effect can be enhanced by the parameters of the two-mode photon numbers and the initial atomic coherence.

scholarly journals On the classical limit of a time-dependent self-consistent field system: Analysis and computation

2017 ◽  
Vol 10 (1) ◽  
pp. 263-298 ◽  
Author(s):  
Shi Jin ◽  
◽  
Christof Sparber ◽  
Zhennan Zhou ◽  
◽  
...  
Keyword(s):  
Classical Limit ◽  
System Analysis ◽  
Time Dependent ◽  
Field System ◽  
Consistent Field ◽  
Self Consistent ◽  
Self Consistent Field

scholarly journals Detecting the work statistics through Ramsey-like interferometry

2014 ◽  
Vol 12 (02) ◽  
pp. 1461007 ◽  
Author(s):  
Laura Mazzola ◽  
Gabriele De Chiara ◽  
Mauro Paternostro
Keyword(s):  
Characteristic Function ◽  
Statistical Mechanics ◽  
Quantum System ◽  
Time Dependent ◽  
Microwave Resonator ◽  
Quantum Level ◽  
Superconducting Qubit ◽  
Equilibrium Statistical Mechanics ◽  
Time Dependent Process ◽  
Work Distribution

Out-of-equilibrium statistical mechanics is attracting considerable interest due to the recent advances in the control and manipulations of systems at the quantum level. Recently, an interferometric scheme for the detection of the characteristic function of the work distribution following a time-dependent process has been proposed [L. Mazzola et al., Phys. Rev. Lett.110 (2013) 230602]. There, it was demonstrated that the work statistics of a quantum system undergoing a process can be reconstructed by effectively mapping the characteristic function of work on the state of an ancillary qubit. Here, we expand that work in two important directions. We first apply the protocol to an interesting specific physical example consisting of a superconducting qubit dispersively coupled to the field of a microwave resonator, thus enlarging the class of situations for which our scheme would be key in the task highlighted above. We then account for the interaction of the system with an additional one (which might embody an environment), and generalize the protocol accordingly.

scholarly journals Hamiltonian Dynamics and Adiabatic Invariants for Time-Dependent Superconducting Qubit-Oscillators and Resonators in Quantum Computing Systems

2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Jeong Ryeol Choi
Keyword(s):  
Hamiltonian Dynamics ◽  
Adiabatic Invariant ◽  
Time Dependent ◽  
Adiabatic Invariants ◽  
Superconducting Qubit ◽  
Computing Systems ◽  
Nanomechanical Resonator ◽  
Von Neumann ◽  
Superconducting Circuit ◽  
Von Neumann Equation

An adiabatic invariant, which is a conserved quantity, is useful for studying quantum and classical properties of dynamical systems. Adiabatic invariants for time-dependent superconducting qubit-oscillator systems and resonators are investigated using the Liouville-von Neumann equation. At first, we derive an invariant for a simple superconducting qubit-oscillator through the introduction of its reduced Hamiltonian. Afterwards, an adiabatic invariant for a nanomechanical resonator linearly interfaced with a superconducting circuit, via a coupling with a time-dependent strength, is evaluated using the technique of unitary transformation. The accuracy of conservation for such invariant quantities is represented in detail. Based on the results of our developments in this paper, perturbation theory is applicable to the research of quantum characteristics of more complicated qubit systems that are described by a time-dependent Hamiltonian involving nonlinear terms.

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