DYNAMICAL PROPERTIES OF MULTI-PHOTON INTERACTION BETWEEN A CAVITY FIELD AND A SINGLE-QUBIT

2013 ◽  
Vol 11 (04) ◽  
pp. 1350038 ◽  
Author(s):  
HEBA KADRY ◽  
NORDIN ZAKARIA ◽  
LEE YEN CHEONG ◽  
MAHMOUD ABDEL-ATY
Keyword(s):  
Evolution Operator ◽  
Cooper Pair ◽  
Time Dependent ◽  
Cooper Pairs ◽  
Cavity Field ◽  
Field Coupling ◽  
Single Qubit ◽  
Cooper Pair Box ◽  
The Mean ◽  
Dynamical Properties

We study the dynamical properties of a cavity field coupling to a Cooper pair box (CPB). We assumed that the CPB is prepared initially in a mixed state with a coherent state for the field. By solving the time-dependent equations using the evolution operator, it shows that mean numbers of Cooper pairs is affected by the detuning. The mean number of Cooper pairs is further enhanced by the multi-photon processes in commonly used cavity field.

Quantum Dynamics and Entropy in a Single-Cooper-Pair Box with a Single-Mode Cavity Field

2003 ◽  
Vol 17 (14) ◽  
pp. 2699-2713 ◽  
Author(s):  
Meng Zhang ◽  
Jian Zou ◽  
Bin Shao
Keyword(s):  
Mixed State ◽  
Pure State ◽  
Quantum Dynamics ◽  
Cooper Pair ◽  
Single Mode ◽  
Quantum Entropy ◽  
Cavity Field ◽  
Cooper Pair Box ◽  
Quantized Field ◽  
Single Mode Cavity

We consider a single-Cooper-pair box biased by a classical voltage and also irradiated by a single-mode quantized field. We assume that the box is initially in a mixed state, and investigate the quantum dynamics of the Cooper-pair box and show that the collapse and revival phenomenon can exist in this system. We also study the quantum entropy of the single-Cooper-pair box and discuss the effects of the different parameters on this quantum entropy. We find that the box, which is initially in a mixed state, may evolve into an almost pure state.

QUANTUM DYNAMICS OF A SINGLE COOPER-PAIR BOX WITH A SINGLE-MODE CAVITY FIELD

2002 ◽  
Vol 16 (31) ◽  
pp. 4767-4774 ◽  
Author(s):  
MENG ZHANG ◽  
JIAN ZOU ◽  
BIN SHAO
Keyword(s):  
Quantum Dynamics ◽  
Cooper Pair ◽  
Single Mode ◽  
Cavity Field ◽  
Field Frequency ◽  
Cooper Pair Box ◽  
Quantized Field ◽  
Single Mode Cavity

We consider a single Cooper-pair box biased by a classical voltage and also irradiated by a single-mode quantized field. We investigate the quantum dynamics of the Cooper-pair box and show that the collapse and revival phenomena can exist in this system, which is sensitive to the detuning between the Josephson energy EJ and cavity field frequency ω.

Dynamics of a nonlinear time-dependent two two-level atoms in a two-mode cavity

2020 ◽  
Vol 18 (03) ◽  
pp. 2050003
Author(s):  
S. T. Korashy ◽  
T. M. El-Shahat ◽  
N. Habiballah ◽  
H. El-Sheikh ◽  
M. Abdel-Aty
Keyword(s):  
Cross Correlation ◽  
Relative Phase ◽  
Coupling Parameter ◽  
Kerr Nonlinearity ◽  
Stark Shift ◽  
Time Dependent ◽  
Cavity Field ◽  
Atomic Inversion ◽  
Field Coupling ◽  
Superposition States

In this paper, we present some properties through two two-level atoms interacting with a two-mode quantized cavity field. We study this system in the presence of detuning parameter, Kerr nonlinearity, Stark shift, relative phase and intensity-dependent atoms-field coupling. Also, the coupling parameter is modulated to be time dependent. The exact solution of this model is given by using the Schrődinger equation when the atoms and the field are initially prepared in superposition states and coherent states, respectively. We employed the results to calculate some aspects such as linear entropy, total atomic inversion and cross-correlation function.

Electronic dynamics in chains with Ornstein–Uhlenbeck correlated disorder

2020 ◽  
Vol 31 (12) ◽  
pp. 2050176
Author(s):  
J. L. S. Soares ◽  
R. D. dos Santos ◽  
F. J. S. Sousa ◽  
M. O. Sales ◽  
F. A. B. F. Moura
Keyword(s):  
Differential Equation ◽  
Evolution Operator ◽  
Mean Square Displacement ◽  
Time Dependent ◽  
Mean Square ◽  
Strong Correlations ◽  
Uhlenbeck Process ◽  
Electronic Dynamics ◽  
Ornstein Uhlenbeck Process ◽  
The Mean

In this paper, we present a detailed study of the electronic dynamics in systems with correlated disorder generated from the Ornstein–Uhlenbeck process (OU). In short, we used numeric methods for solving the time-dependent Schrödinger equation. We apply a Taylor’s expansion of the evolution operator in order to solve the differential equation. We calculate some typical tools, such as the participation function [Formula: see text], the mean square displacement [Formula: see text] and the probability of return [Formula: see text]. In our analysis, we show that for low correlations the system behaves as in the standard Anderson model (i.e. all eigenstates are localized). For strong correlations, our results suggest the existence of a quasi-ballistic dynamics.

MOVING FOUR-LEVEL ATOM INTERACTING WITH A SINGLE-MODE FIELD WITH INTENSITY DEPENDENT COUPLING

2004 ◽  
Vol 18 (20n21) ◽  
pp. 2901-2914
Author(s):  
R. A. ZAIT
Keyword(s):  
Photon Number ◽  
Single Mode ◽  
Cavity Field ◽  
Field Coupling ◽  
Mode Field ◽  
Level Atom ◽  
The Mean ◽  
Reduced Density ◽  
Field Wave ◽  
Intensity Dependent Coupling

We study the interaction of a moving four-level atom with a single mode cavity field. Involving intensity dependent coupling, the atom-field wave function and the reduced density matrix of the field are obtained when the atom is initially prepared in a coherent superposition of the upper and ground states and the field is initially in a coherent state. The influence of the intensity dependent atom-field coupling and of the detuning on the collapse and revival phenomenon of the time evolution of statistical aspects, such as the mean photon number, the second-order correlation function of the field, the momentum increment and momentum diffusion, are investigated. It is found that, for the nonresonant case, the detuning between the field and the atom has a significant influence which leads to increasing the collapse time with decreasing amplitude. Numerical computations and discussion of the results are presented.

scholarly journals Multiplicity, Parity and Angular Momentum of a Cooper Pair in Unconventional Superconductors of D4h Symmetry: Sr2RuO4 and Fe-Pnictide Materials

Symmetry ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1435
Author(s):  
Victor G. Yarzhemsky
Keyword(s):  
Angular Momentum ◽  
Cooper Pair ◽  
Point Group ◽  
Group Symmetry ◽  
Cooper Pairs ◽  
Group Approach ◽  
Angular Momentum Projection ◽  
Space Group ◽  
Unconventional Superconductors ◽  
Even Pairs

Sr2RuO4 and Fe-pnictide superconductors belong to the same point group symmetry D4h. Many experimental data confirm odd pairs in Sr2RuO4 and even pairs in Fe-pnictides, but opposite conclusions also exist. Recent NMR results of Pustogow et al., which revealed even Cooper pairs in Sr2RuO4, require reconsideration of symmetry treatment of its SOP (superconducting order parameter). In the present work making use of the Mackey–Bradley theorem on symmetrized squares, a group theoretical investigation of possible pairing states in D4h symmetry is performed. It is obtained for I4/mmm , i.e., space group of Sr2RuO4, that triplet pairs with even spatial parts are possible in kz direction and in points M and Y. For the two latter cases pairing of equivalent electrons with nonzero total momentum is proposed. In P4/nmm space group of Fe- pnictides in point M, even and odd pairs are possible for singlet and triplet cases. It it shown that even and odd chiral states with angular momentum projection m=±1 have nodes in vertical planes, but Eg is nodal , whereas Eu is nodeless in the basal plane. It is also shown that the widely accepted assertion that the parity of angular momentum value is directly connected with the spatial parity of a pair is not valid in a space-group approach to the wavefunction of a Cooper pair.

scholarly journals Large Time Decay of Solutions to a Linear Nonautonomous System in Exterior Domains

Mathematics ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 841
Author(s):  
Toshiaki Hishida
Keyword(s):  
Evolution Operator ◽  
Large Time ◽  
Rigid Motion ◽  
Time Dependent ◽  
Energy Relation ◽  
Exterior Domains ◽  
Decay Properties ◽  
Decay Of Solutions ◽  
Whole Space ◽  
Expository Paper

In this expository paper, we study Lq-Lr decay estimates of the evolution operator generated by a perturbed Stokes system in n-dimensional exterior domains when the coefficients are time-dependent and can be unbounded at spatial infinity. By following the approach developed by the present author for the physically relevant case where the rigid motion of the obstacle is time-dependent, we clarify that some decay properties of solutions to the same system in whole space Rn together with the energy relation imply the desired estimates in exterior domains provided n≥3.

scholarly journals SCALING INVARIANCE IN A TIME-DEPENDENT ELLIPTICAL BILLIARD

2012 ◽  
Vol 22 (09) ◽  
pp. 1250207 ◽  
Author(s):  
DIEGO F. M. OLIVEIRA ◽  
MARKO ROBNIK
Keyword(s):  
Integrable System ◽  
Average Velocity ◽  
Moving Boundary ◽  
Time Dependent ◽  
Scaling Invariance ◽  
Energy Growth ◽  
Dynamical Properties ◽  
Scaling Arguments

We study some dynamical properties of a classical time-dependent elliptical billiard. We consider periodically moving boundary and collisions between the particle and the boundary are assumed to be elastic. Our results confirm that although the static elliptical billiard is an integrable system, after introducing time-dependent perturbation on the boundary the unlimited energy growth is observed. The behavior of the average velocity is described using scaling arguments.

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