Here, a scheme that realizes controlled interactions between two distant quantum dot spins is proposed. In comparison with studies devoted to the static quantum entanglement, the dynamical point of view of entanglement has been less considered in the last two decades [8,9,10,11,12,13,14]. The corresponding nonequilibrium thermodynamic cost is quantified by the nonzero entropy production rate. A 74, 052105 (2006), S.C. Benjamin, S. Bose, Phys. Out of equilibrium entangled states are generated and manipulated by means of many-body Hamiltonians. Y.) Akhtarshenas, H. This entanglement can be confirmed by testing Bell's inequalities involving any two spins in the solid. We consider the three-ligand spin-star structure through homogeneous Heisenberg interactions (XXX-3LSSS) in the framework of dynamical pairwise entanglement. (2007), M.G. Coffman, J. Kundu, and W. K. Wootters, Phys. Compared with the periodical XXZ model, the critical temperature is significantly improved for the topological XXZ model. Phys. 777.8 777.8 777.8 777.8 777.8 1000 1000 777.8 666.7 555.6 540.3 540.3 429.2] /Name/F10 stream We also investigate the anisotropic XY model and find that the above conclusion more or less holds. A scheme is proposed for the generation of two-atom maximally entangled states and realization of quantum logic gates and teleportation with cavity QED. On the other hand, the energy detuning of the two qubits, when used in a compensatory way with the nonequilibrium condition, can lead to significant enhancement of the steady-state entanglement in some parameter regimes. 111, 230503 (2013), Monras, A., Illuminati, F.: Measurement of damping and temperature: Precision bounds in Gaussian dissipative channels. conditions respectively and find the two best models in these conditions. 105, 020503 (2010), Ollivier, H., Zurek, W.H. Here, we introduce the most used model, the Heisenberg isotropic XY model in a uniform magnetic field as a reference model and we call it ref. Phys. Correspondence to : Quantum noise limited and entanglement-assisted magnetometry. quantum effects in the system can be maintained at high temperatures, where we 777.8 777.8 777.8 888.9 888.9 777.8 777.8 777.8 777.8 777.8 777.8 777.8 777.8 777.8 To read the full-text of this research, you can request a copy directly from the author. 562.5 562.5 562.5 562.5 562.5 562.5 562.5 562.5 562.5 562.5 562.5 312.5 312.5 342.6 For both the nearest-neighbor spins and the next nearest-neighbor spins, special attention is paid to the dependence of entanglement and QD on the anisotropic parameter (Formula presented.) << We show that quantum discord is finite for all studied spin pairs in the Luttinger liquid phase. Lett. Here, from the view of entanglement propagation, we disclose the signature of fractional QST possibilities. Math. In the scheme the cavity is only virtually excited and thus the requirement on the quality factor of the cavities is greatly loosened. We also find that weak inter-qubit coupling and high base temperature or chemical potential of the baths can strongly suppress the steady-state entanglement and coherence, regardless of the strength of the nonequilibrium condition. 47, 631 (1928). S. Hill and W. K. Wootters, Phys. 0 0 0 0 0 0 0 0 0 0 0 0 675.9 937.5 875 787 750 879.6 812.5 875 812.5 875 0 0 812.5 /FirstChar 33 Gao, X.C. 500 555.6 527.8 391.7 394.4 388.9 555.6 527.8 722.2 527.8 527.8 444.4 500 1000 500 We find that at a given temperature and magnetic field strength, the mirror symmetry of the two fields about the x-y plane is a necessary condition for maximum entanglement. A 57, 120 curve is also the smoothest curve in all the curves, that is to say, the entangled, call it model 2. Finally, we demonstrate that our results for the system in an infinite bath also hold qualitatively when the system is in contact with a finite bath. Guidance Control Dyn. ... As reported in Ref. Rev. Through studying different parameters effect on χ, it presents that we can properly turn the values of B, b, Jz, Δ or adjust the temperature T to obtain a valid dense coding capacity (χ satisfies χ > 1). 82, 1345 (1999). Practical application of the generalized Bell's theorem in the so-called key distribution process in cryptography is reported. XX chain with an inhomogeneous external magnetic field. Two genuinely quantum mechanical models for an antiferromagnetic linear chain with nearest neighbor interactions are constructed and solved exactly, in the sense that the ground state, all the elementary excitations and the free energy are found. DiVincenzo, Phys. MathSciNet  The constants of motion of system imply the existence of a decomposition of the system’s Hilbert space ℋ into a direct sum of three infinite dimensional sub-spaces, as ℋ=ℋ(1)⊕ℋ(2)⊕ℋ(3). Google Scholar, Helstrom, C.W. A 90, 063838 (2014), Pezzé, L., Smerzi, A.: Entanglement, nonlinear dynamics, and the Heisenberg limit. On the contrary, W states cannot be generated from the time evolution of a ligand "one-particle" state (LOPS). 892.9 1138.9 892.9] endobj Rev. Cirac, A. Acin, M. Lewenstein, J. Wehr, Phys. Lett. 83, 2274 ͑1999͒. /Subtype/Type1 is dependent on future refinements of conventional silicon electronics. 766.7 715.6 766.7 0 0 715.6 613.3 562.2 587.8 881.7 894.4 306.7 332.2 511.1 511.1 Lett. 30 0 obj 0 0 0 0 0 0 0 615.3 833.3 762.8 694.4 742.4 831.3 779.9 583.3 666.7 612.2 0 0 772.4 1444.4 555.6 1000 1444.4 472.2 472.2 527.8 527.8 527.8 527.8 666.7 666.7 1000 1000 Phys. An important insight to understand the process of QST can be fulfilled by considering the dynamical behavior of its entanglement content. It is inherently quantum mechanical and has no classical analogue. China, Shanghai Key Lab for Astrophysics, Shanghai, 200234, P.R. We study the entanglement in the quantum Heisenberg XY model in which the so-called W entangled states can be generated for 3 or 4 qubits. O'Connor and W.K. For the isotropic system, all types of entanglement and 588.6 544.1 422.8 668.8 677.6 694.6 572.8 519.8 668 592.7 662 526.8 632.9 686.9 713.8 Indeed, these states are the initial states most commonly used in studies of entanglement dynamics (see, for example, Refs. Master’s thesis, University of Waterloo (2004), Banchi, L., Giorda, P., Zanardi, P.: Quantum information-geometry of dissipative quantum phase transitions. Rev. /Name/F3 Rev. 80, 2245 (1998), X.G. Επίσης παρατηρούμε ότι η θερμοκρασία του περιβάλλοντος μπορεί να αποτελέσει παράγοντα ελέγχου των ανωτέρω φαινομένων.