Quantum-classical equivalence and ground-state factorization

  title={Quantum-classical equivalence and ground-state factorization},
  author={Jahanfar Abouie and Reza Sepehrinia},
  journal={Europhysics Letters},
We have performed an analytical study of quantum-classical equivalence for quantum XY-spin chains with arbitrary interactions to explore the classical counterpart of the factorizing magnetic fields that drive the system into a separable ground state. We demonstrate that the factorizing line in the parameter space of a quantum model is equivalent to the so-called natural boundary that emerges in mapping the quantum XY-model onto the two-dimensional classical Ising model. As a result, we show… 



Quantum Discord in the Ground State of Spin Chains

The ground state of a quantum spin chain is a natural playground for investigating correlations. Nevertheless, not all correlations are genuinely of quantum nature. Here we review the recent progress

Ground-state factorization and correlations with broken symmetry

We show how the phenomenon of factorization in a quantum many-body system is of collective nature. To this aim we study the quantum discord Q in the one-dimensional XY model in a transverse field. We

Theory of ground state factorization in quantum cooperative systems.

The method allows us to determine rigorously the existence, location, and exact form of separable ground states in a large variety of spin models belonging to different universality classes.

Studying quantum spin systems through entanglement estimators.

At the quantum-critical point, a deep minimum in the pairwise-to-globalEntanglement ratio shows that multispin entanglement is strongly enhanced; moreover this signature represents a novel way of detecting the quantum phase transition of the system, relying entirely on entanglements estimators.

Equivalence between the two-dimensional Ising model and the quantum XY chain with randomness and with open boundary

The equivalence between the two-dimensional Ising model and the one-dimensional quantum XY model is generalized to the cases with alternating/random interactions and with periodic/free boundary

Quantum discord in finite XY chains

We examine the quantum discord between two spins in the exact ground state of finite spin-1/2 arrays with anisotropic XY couplings in a transverse field B. It is shown that in the vicinity of the

Criticality, factorization, and long-range correlations in the anisotropic XY model

We study the long-range quantum correlations in the anisotropic XY-model. By first examining the thermodynamic limit we show that employing the quantum discord as a figure of merit allows one to

Effects of a space modulation on the behavior of a 1D alternating Heisenberg spin-1/2 model

The effects of a magnetic field (h) and a space modulation (δ) on the magnetic properties of a one-dimensional antiferromagnetic–ferromagnetic Heisenberg spin-1/2 model have been studied by means of

Topological quantum phase transition in bond-alternating spin-12Heisenberg chains

We investigate string correlations in an infinite-size spin-1/2 bond-alternating Heisenberg chain. By employing the infinite matrix product state representation with the infinite time evolving block