Zobrazeno 1 - 10
of 1 697
pro vyhledávání: '"Peschel, I."'
Publikováno v:
J. Stat. Mech. (2009) P02011
We study solvable spin chains where either fields or couplings vary linearly in space and create a sandwich-like structure of the ground state. We find that the entanglement entropy between two halves of a chain varies logarithmically with the interf
Externí odkaz:
http://arxiv.org/abs/0810.3788
Publikováno v:
J. Stat. Mech. (2008) P01023
We study zero-temperature XX chains and transverse Ising chains and join an initially separate finite piece on one or on both sides to an infinite remainder. In both critical and non-critical systems we find a typical increase of the entanglement ent
Externí odkaz:
http://arxiv.org/abs/0711.0289
Autor:
Eisler, V., Peschel, I.
Publikováno v:
J. Stat. Mech. (2007) P06005
We study free electrons on an infinite half-filled chain, starting in the ground state with a bond defect. We find a logarithmic increase of the entanglement entropy after the defect is removed, followed by a slow relaxation towards the value of the
Externí odkaz:
http://arxiv.org/abs/cond-mat/0703379
Publikováno v:
J. Phys. A 24 (1991) L1229
We study two-dimensional systems with boundary curves described by power laws. Using conformal mappings we obtain the correlations at the bulk critical point. Three different classes of behaviour are found and explained by scaling arguments which als
Externí odkaz:
http://arxiv.org/abs/cond-mat/0106602
Publikováno v:
J. Magn. Magn. Mater. 240, 349-351 (2002)
Properties of magnetic films are studied in the framework of Ising models. In particular, we discuss critical phenomena of ferromagnetic Ising films with straight lines of magnetic adatoms and straight steps on the surface as well as phase diagrams o
Externí odkaz:
http://arxiv.org/abs/cond-mat/0105583
Publikováno v:
Eur. Phys. J. B 18, 655-661 (2000)
The influence of surface defects on the critical properties of magnetic films is studied for Ising models with nearest-neighbour ferromagnetic couplings. The defects include one or two adjacent lines of additional atoms and a step on the surface. For
Externí odkaz:
http://arxiv.org/abs/cond-mat/0007499
Publikováno v:
Ann. Physik (Leipzig) 8 (1999) 153
The spectra which occur in numerical density-matrix renormalization group (DMRG) calculations for quantum chains can be obtained analytically for integrable models via corner transfer matrices. This is shown in detail for the transverse Ising chain a
Externí odkaz:
http://arxiv.org/abs/cond-mat/9810174
Autor:
Kaulke, M., Peschel, I.
Publikováno v:
Eur. Phys. J. B 5 (1998) 727
The spin one-half Heisenberg chain with $U_q[SU(2)]$ symmetry is studied via density-matrix renormalization. Ground-state energy and $q$-symmetric correlation functions are calculated for the non-hermitian case $q=\exp(i\pi/(r+1))$ with integer $r$.
Externí odkaz:
http://arxiv.org/abs/cond-mat/9802175
Autor:
Honecker, A., Peschel, I.
Publikováno v:
Physica A239 (1997) 509-530
We re-examine a two-dimensional forest-fire model via Monte-Carlo simulations and show the existence of two length scales with different critical exponents associated with clusters and with the usual two-point correlation function of trees. We check
Externí odkaz:
http://arxiv.org/abs/cond-mat/9609105
Autor:
Honecker, A., Peschel, I.
Publikováno v:
J.Statist.Phys. 88 (1997) 319-345
The hopping motion of classical particles on a chain coupled to reservoirs at both ends is studied for parallel dynamics with arbitrary probabilities. The stationary state is obtained in the form of an alternating matrix product. The properties of on
Externí odkaz:
http://arxiv.org/abs/cond-mat/9606053