Energy eigenvalues and order parameters are calculated by exact diagonalization for the transverse Ising model on square lattices of up to 6x6 sites. Finite-size scaling is used to estimate the critical parameters of the model, confirming universality with the three-dimensional classical Ising model. Critical amplitudes are also estimated for both the energy gap and the ground-state energy. PAC...

The magnetic analog of the Grüneisen parameter, i.e., the magnetocaloric effect, is a valuable tool for studying field-tuned quantum phase transitions. We determine the magnetic Grüneisen parameter of the one-dimensional random transverse-field Ising model, focusing on its lowtemperature behavior at the exotic infinite-randomness quantum critical point and in the associated quantum Griffiths ph...

We have considered a numerical scheme for the calculation of the equilibrium properties of spin-12 XY chains. Within its frames it is necessary to solve in the last resort only the 2N × 2N eigenvalue and eigenvector problem but not the 2 × 2 one as for an arbitrary system consisting of N spins 1 2 . To illustrate the approach we have presented some new results. Namely, the xx dynamic structure ...

We propose a physical setup that can be used to simulate the quantum dynamics of the Ising model in a transverse field. Building on currently available technology, our scheme consists of electrons which float on a superfluid helium film covering a suitable substrate and interact via Coulomb forces. At low temperatures, the system will stay near its ground state where its Hamiltonian is equivale...

We study D-branes transverse to an abelian orbifold C/Zn × Zn. The moduli space of the gauge theory on the D-branes is analyzed by combinatorial calculation based on toric geometry. It is shown that the calculation is related to a problem to count the number of ground states of an antiferromagnetic Ising model. The lattice on which the Ising model is defined is a triangular one defined on the M...

Numerical results for the concurrence and bounds on the localizable entanglement are obtained for the square lattice spin-1/2 XXZ-model and the transverse field Ising-model at low temperatures using quantum Monte Carlo.

An analysis is presented of the phase transition of the quantum Ising model with transverse field on the d-dimensional hypercubic lattice. It is shown that there is a unique sharp transition. The value of the critical point is calculated rigorously in one dimension. The first step is to express the quantum Ising model in terms of a (continuous) classical Ising model in d + 1 dimensions. A so-ca...