Abstract The orthogonality time is examined for different initial states settings interacting locally with types of spin interaction: XX , Ising and anisotropic models. It shown that the number increases, consequently decreases as environment qubits increase. shortest displayed chain model, while largest model. external field increases numbers orthogonality, Dzyaloshinsky–Moriya interaction ort...

We calculate a nonequilibrium steady state of a quantum XX chain in the presence of dephasing and driving due to baths at chain ends. The obtained state is exact in the limit of weak driving while the expressions for oneand two-point correlations are exact for an arbitrary driving strength. In the steady state the magnetization profile and the spin current display diffusive behavior. The spin–s...

We study the long time behavior of the zz and xx time dependent autocorrelation function of the spin 1/2 XXZ chain at T = ∞ by exact diagonalizations on a chain of 16 sites. We find that the numerical results for the zz correlation are very well fit by the formula t−d[A+Be−γ(t−t0) cos Ω(t− t0)]. From this we estimate d as a function of the anisotropy of the chain and study the crossover from ba...

In this work, we study temperature sensing with finite-sized strongly correlated systems exhibiting quantum phase transitions. We use the Fisher information (QFI) approach to quantify sensitivity in estimation, and apply a finite-size scaling framework link critical exponents of system around points. numerically calculate QFI points for two experimentally-realizable systems: spin-1 Bose-Einstei...

A continuum medium approach is proposed to describe the finite size dependent effects for the 1D isotropic Heisenberg ferromagnet. The results are compared to the exact Bethe ansatz solution for the finite chain. The approach is shown to adequately account for the behaviour of the eigenfunctions and eigenenergies. The continuum is obtained by integration in Fourier space via introduction of cut...

The dynamical behavior of a star network of spins, wherein each of N decoupled spins interact with a central spin through non uniform Heisenberg XX interaction is exactly studied. The time-dependent Schrödinger equation of the spin system model is solved starting from an arbitrary initial state. The resulting solution is analyzed and briefly discussed.

We consider a multiple integral representation for a one-parameter generating function of the finite temperature Sz-Sz correlation functions of the antiferromagnetic spin-1/2 XXZ chain in the XX limit and in the Ising limit. We show how in these limits the multiple integrals reduce to single integrals, thereby reproducing known results. PACS: 05.30.-d, 75.10.Pq †e-mail: [email protected]...

We consider the spin1 2 XY chain in a transverse field with regularly varying exchange interactions and on-site fields. In two limiting cases of the isotropic (XX) and extremely anisotropic (Ising) exchange interaction the thermodynamic quantities are calculated rigorously with the help of continued fractions. We discuss peculiarities of the low-temperature magnetic properties and a possibility...

We critically examine the possibility of determining the parity of the Θ + (1540) from the reactions N N → Θ + Y (Y = Λ, Σ) recently discussed in the literature. Specifically, we study the energy dependence of those observables that were suggested to be the most promising ones to unravel the parity of the Θ + , namely the spin correlation coefficient A xx , and the spin transfer coefficient D x...