Thermal Entanglement and Dense Coding in Two-Qubit XX Spin Chain under an Arbitrary Magnetic Field

2013 ◽  
Vol 446-447 ◽  
pp. 986-991
Author(s):  
Hai Lin Huang ◽  
Zhao Yu Sun
Keyword(s):  
Magnetic Field ◽  
Thermal State ◽  
Arbitrary Orientation ◽  
Dense Coding ◽  
Thermal Entanglement ◽  
Optimal Direction ◽  
Optimal Dense Coding ◽  
Arbitrary Magnetic Field ◽  
Coding Capacity ◽  
The Magnetic Field

The effect of arbitrary orientation in the magnetic field on the entanglement and dense coding of a two-qubit XX model is investigated. The concurrence and optimal dense coding capacity are calculated for different orientations of the magnetic field. It is found that the entanglement can be maximized by rotating the magnetic field to an optimal direction at given temperature. Furthermore, there exists critical concurrence Cc, beyond which the thermal state is unfeasible for optimal dense coding.

scholarly journals THERMAL ENTANGLEMENT IN A TWO-QUTRIT SYSTEM WITH NONLINEAR COUPLING UNDER NONUNIFORM EXTERNAL MAGNETIC FIELD

2008 ◽  
Vol 06 (04) ◽  
pp. 867-884 ◽  
Author(s):  
IMAN SARGOLZAHI ◽  
SAYYED YAHYA MIRAFZALI ◽  
MOHSEN SARBISHAEI
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Lower Bounds ◽  
Threshold Temperature ◽  
Nonlinear Coupling ◽  
Dense Coding ◽  
Thermal Entanglement ◽  
Finite Dimensional ◽  
Coding Capacity ◽  
The Magnetic Field

We study the thermal entanglement of a 2-qutrit spin chain with nonlinear coupling in the presence of nonuniform magnetic field. Thermal entanglement of an arbitrary (finite-dimensional) m-partite system vanishes at some finite threshold temperature Ts. We investigate the dependence of Ts on the system's parameters, i.e. the nonlinear coupling and the magnetic field, for this 2-qutrit system. In addition, we compare two lower bounds of I-concurrence for this system and also study its dense coding capacity as a function of system's parameters.

Effect of The Orientation of The Magnetic Field on The Giant Magnetoresistance of Fe/Cr Superlattices

1995 ◽  
Vol 384 ◽  
Author(s):  
V.V. Ustinov ◽  
V.I. Minin ◽  
L.N. Romashev ◽  
A.B. Semerikov ◽  
A.R. Del
Keyword(s):  
Magnetic Field ◽  
Molecular Beam Epitaxy ◽  
Field Strength ◽  
Magnetization Curve ◽  
Giant Magnetoresistance ◽  
Molecular Beam ◽  
Orientation Dependence ◽  
Arbitrary Orientation ◽  
Strength Dependence ◽  
The Magnetic Field

ABSTRACTWe study the magnetoresistance of [Fe/Cr]30/MgO superlattices grown by molecular beam epitaxy at a various magnetic field directions. The theory of the orientation dependence of the effect is developed. It is shown that the magnetic field strength dependence of magnetoresistance can be calculated for arbitrary orientation of magnetic field if this dependence is known for in-plane and perpendicular-to-plane magnetic fields. It is noted that the magnetization curve can be obtained by making use of the results of the magnetoresistance measurements.

scholarly journals Thermodynamic Cost of Quantum transfers

2021 ◽  
Author(s):  
Forouzan Mirmasoudi ◽  
Sodeif Ahadpour
Keyword(s):  
Excited States ◽  
Energy Cost ◽  
Quantum Fisher Information ◽  
Quantum Correlations ◽  
Spin Squeezing ◽  
Quantum Systems ◽  
Control Parameters ◽  
Dense Coding ◽  
Optimal Dense Coding ◽  
Coding Capacity

Abstract In this work, we will study thermodynamic cost of dense coding. In this regard, a scheme is proposed for quantum channel where is induced from two initially uncorrelated thermal quantum systems. At first, the quantum Fisher information and spin squeezing is used to quantify the correlation dynamics over the system. The system reveals that the dynamics of quantum correlations depends crucially on specific energy and temperature. Also, they can be utilized as control parameters for optimal dense coding. Several interesting features of the variations of the energy cost and the dense coding capacity are obtained. It can keep its own valid capacity value in a broad range of temperature by increasing in the energy value of excited states. Also, we can identify valid dense coding with the help of calculating energy cost in the system. Using this approach, identifying a critical point of this model in dense coding capacity quality can be very effective.

The dynamics of tripartite quantum correlations under Ornstein–Uhlenbeck noise

2018 ◽  
Vol 32 (31) ◽  
pp. 1850381 ◽  
Author(s):  
Jing Yang ◽  
Qi-Xiong Mu ◽  
Yan-Xia Huang
Keyword(s):  
Magnetic Field ◽  
Sudden Death ◽  
Quantum Correlation ◽  
Quantum Correlations ◽  
Time Limit ◽  
Entanglement Sudden Death ◽  
Thermal Entanglement ◽  
Short Time ◽  
The Magnetic Field ◽  
Markov Limit

The dynamics of the tripartite thermal entanglement measured by Negativity (N) and the tripartite quantum correlation described by measurement-induced disturbance (MID) under Ornstein–Uhlenbeck noise are investigated. This study has found that the tripartite N and MID can be preserved more effectively in the non-Markovian environment than in the short-time limit and the Markov limit cases. The short-time limit is a better approximation than the Markov limit. MID vanishes only in the asymptotic limit, while entanglement sudden death may occur, and the decreasing duration of MID far outweighs entanglement. This implies that MID is more robust than Negativity. As the noise bandwidth increases, the disentanglement time and the decay time of MID are significantly shorter. The increase of XZX[Formula: see text]+[Formula: see text]YZY three-site interaction is more effective than XZY−YZX three-site interaction to enhance Negativity and MID as well as the disentanglement time. The magnetic field diminishes Negativity and MID, but has no significant influence on the decreasing durations of both Negativity and MID.

Magnetohydrodynamic duct flow in a uniform transverse magnetic field of arbitrary orientation

1971 ◽  
Vol 48 (3) ◽  
pp. 429-461 ◽  
Author(s):  
C. J. N. Alty
Keyword(s):  
Magnetic Field ◽  
Pressure Gradient ◽  
Transverse Magnetic Field ◽  
Potential Distribution ◽  
Transverse Magnetic ◽  
Arbitrary Orientation ◽  
Axial Pressure Gradient ◽  
Viscous Shear ◽  
The Magnetic Field ◽  
Pressure Driven

The paper presents an approximate analysis for high Hartmann number of the flow of an electrically conducting, incompressible fluid in a duct of square crosssection, having one pair of opposite walls insulating, and the other pair perfectly conducting and inclined at arbitrary orientation to a uniform transverse magnetic field. The flow is considered to be either pressure-driven with the two perfectly conducting electrodes short-circuited together or electrically driven by a potential difference applied between these electrodes in the absence of axial pressure gradient. The paper describes experiments on the pressure-driven, short circuited case using mercury in copper ducts to investigate the variation of the streamwise pressure gradient and of the potential distribution along one insulating wall with orientation, magnetic field and flow rate.At general orientations the analysis suggests and the experiments confirm the existence of regions of stationary fluid in the corners of the duct, together with viscous shear layers parallel to the magnetic field. For the case in which the electrodes are parallel to the magnetic field the experimental results for the pressure gradient, but not those for the potential distribution, agree reasonably well with Hunt & Stewartson's (1965) asymptotic solution. Both pressure gradient and potential results agree closely with the analysis by Hunt (1965) of the case in which the electrodes are perpendicular to the magnetic field.

scholarly journals Thermal entanglement in a {Cu3} single molecular magnet in the magnetic field

2013 ◽  
Vol 62 (19) ◽  
pp. 190302
Author(s):  
Li Ji-Qiang ◽  
Cheng Zhi ◽  
Zhou Bin
Keyword(s):  
Magnetic Field ◽  
Molecular Magnet ◽  
Thermal Entanglement ◽  
The Magnetic Field
Sign in / Sign up

Export Citation Format

Share Document