Groupe de Physique Statistique/ Arbeitsgruppe Statistische Physik

Equipe 106, Institut Jean Lamour

                     
Startseite
Zugang
Mitarbeiter
Publikationen
Articles in peer-reviewed journals
Letters
Invited proceedings
Proceedings
Unpublished
Ph.D
Habilitation
Epistemology, history of sciences
Pedagogical papers
Buch
Book edition
Book chapters
Vulgarisation
Seminare
Ateliers
Rencontres
Schulen
International
Arbeitsgruppen
Stellen, Doktorarbeiten
Lehre

Articles in peer-reviewed journals

Gradient critical phenomena in the Ising quantum chain
Platini T., Karevski D., Turban L.
J. Phys. A: Math. Theor. 40 (2007) 1467 - 1479
DOI : 10.1088/1751-8113/40/7/004
ArXiv : cond-mat/0611213 [PDF]
HAL : hal-00112421

We consider the behaviour of a critical system in the presence of a gradient perturbation of the couplings. In the direction of the gradient an interface region separates the ordered phase from the disordered one. We develop a scaling theory for the density profiles induced by the gradient perturbation which involves a characteristic length given by the width of the interface region. The scaling predictions are tested in the framework of the mean-field Ginzburg-Landau theory. Then we consider the Ising quantum chain in a linearly varying transverse field which corresponds to the extreme anisotropic limit of a classical two-dimensional Ising model. The quantum Hamiltonian can be diagonalized exactly in the scaling limit where the eigenvalue problem is the same as for the quantum harmonic oscillator. The energy density, the magnetization profile and the two-point correlation function are studied either analytically or by exact numerical calculations. Their scaling behaviour are in agreement with the predictions of the scaling theory.



Seitenanfang