Related papers: Quantum correlations in a cluster spin model with …
Recently, along with the development of quantum information, quantum entanglemant became a hot topic of people. Quantum entanglemant is one of the most amazing phenomenon in quantum mechanics that is totally different from classical…
We study the low energy states of finite spin chains with isotropic (Heisenberg) and anisotropic (XY and Ising-like) exchange interaction with uniform and non-uniform coupling constants. We show that for an odd number of sites a spin…
The phase diagrams of the spin-$3/2$ Blume-Capel model with competing short and long-range interactions were studied through the free energy density obtained by analytical methods. The competition emerges when positive short-range…
We introduce an exact spin transformation that maps frustrated Z_{i,j}Z_{i,j+1} and X_{i,j}X_{i+1,j} spin interactions along the rows and columns of the quantum compass model (QCM) on an LxL square lattice to (L-1)x(L-1) quantum spin models…
We discuss spin-$S$ antiferromagnetic Heisenberg chains with three-spin interactions, next-nearest-neighbor interactions, and bond alternation. First, we prove rigorously that there exist parameter regions of the exact dimerized ground…
We study entanglement and spin squeezing in the ground state of three qubits interacting via the transverse Ising model. We give analytical results for the entanglement and spin squeezing, and a quantitative relation between the…
Finding an exact solution for a realistic interacting quantum many-body problem is often challenging. There are only a few problems where an exact solution can be found, usually in a narrow parameter space. Here, we propose a spin-$1/2$…
In this paper we analize a family of one dimensional fully analytically solvable models, named the n-cluster models in a transverse magnetic field, in which a many-body cluster interaction competes with a uniform transverse magnetic field.…
Quantum discord is a general measure of bipartite quantum correlations with a potential role in quantum information processing tasks. Spin clusters serve as ideal candidates for the implementation of some of the associated protocols. In…
We examine the behavior of quantum correlations of spin pairs in a finite anisotropic $XY$ spin chain immersed in a transverse magnetic field, through the analysis of the quantum discord and the conventional and quadratic one…
We analyze the behavior of steady-state quantum correlations (QCs) in the spin-1/2 transverse field XY chains analytically, in terms of quench dynamics at zero-temperature. We show that steady-state QCs are strikingly greater than the…
The anisotropic Heisenberg two-spin-1/2 model in an inhomogeneous magnetic field with both antisymmetric Dzyaloshinsky-Moriya and symmetric Kaplan-Shekhtman-Entin-Wohlman-Aharony cross interactions is considered at thermal equilibrium.…
We study the simple Hamiltonian, $H=-K(S_{1z}^2 +S_{2z}^2)+ \lambda\vec S_1\cdot\vec S_2$, of two, large, coupled spins which are taken equal, each of total spin $s$ with $\lambda$ the exchange coupling constant. The exact ground state of…
Magnetic systems with frustration often have large classical degeneracy. We show that their low-energy physics can be understood as dynamics within the space of classical ground states. We demonstrate this mapping in a family of quantum…
We discuss a generalization of the conditional entropy and one-way information deficit in quantum systems, based on general entropic forms. The formalism allows to consider simple entropic forms for which a closed evaluation of the…
We examine the entanglement of the ground state of a 16-site spin-1/2 pyrochlore cluster in the quantum spin ice regime via various calculations of ${\cal I}$-concurrence. Exact ground state solutions to a quantum spin Hamiltonian with four…
We study the correlation function and concurrence for the eigenstates with zero spin of engineered Heisenberg models to explore the entanglement property. It is shown that the total nearest neighbor (NN) correlation function of zero-spin…
We consider a spin-1/2 XY chain in a transverse (z) field with multi-site interactions. The additional terms introduced into the Hamiltonian involve products of spin components related to three adjacent sites. A Jordan-Wigner transformation…
We address the question of the role of quantum correlations beyond entanglement in context of quantum magnetometry. To this end, we study the evolution of the quantum discord, measured by the rescaled discord, of two electron-spin qubits…
We theoretically investigate the ground-state properties of a quantum dot defined on the surface of a strong three-dimensional time-reversal invariant topological insulator. Confinement is realized by ferromagnetic barriers and Coulomb…