Quantum critical dynamics of the random transverse-field Ising spin chain
HLRZ, Forschungszentrum Jülich - 52425 Jülich, Germany
2 Research Institute for Solid State Physics - H-1525 Budapest, P.O.Box 49, Hungary, Institut für Theoretische Physik, Universität zu Köln - 50937 Köln, Germany
Accepted: 10 June 1997
Dynamical correlations of the spin and the energy density are investigated in the critical region of the random transverse-field Ising chain by numerically exact calculations in large finite systems . The spin-spin autocorrelation function is found to decay proportionally to and in the bulk and on the surface, respectively, with xm and the bulk and surface magnetization exponents, respectively. On the other hand, the critical energy-energy autocorrelation functions have a power law decay, which are characterized by novel critical exponents in the bulk and at the surface, respectively. The numerical results are compared with the predictions of a scaling theory.
PACS: 05.50.+q – Lattice theory and statistics; Ising problems / 64.60.Ak – Renormalization-group, fractal, and percolation studies of phase transitions / 68.35.Rh – Phase transitions and critical phenomena
© EDP Sciences, 1997