Articles dans des revues à comité de lecture
|Numerical evidence of the double-Griffiths phase of the random quantum Ashkin-Teller chain|
|Chatelain C., Voliotis D.|
|Eur. Phys. J. B 89 (2016) 18|
|DOI : 10.1140/epjb/e2015-60593-3|
|ArXiv : arxiv:1506.00416 [PDF]|
|HAL : hal-01158447|
The random quantum Ashkin-Teller chain is studied numerically by means of time-dependent Density-Matrix Renormalization Group. The critical lines are estimated as the location of the peaks of the integrated autocorrelation times, computed from spin-spin and polarization-polarization autocorrelation functions. Disorder fluctuations of magnetization and polarization are observed to be maximum on these critical lines. Entanglement entropy leads to the same phase diagram, though with larger Finite-Size effects. The decay of spin-spin and polarization-polarization autocorrelation functions provides numerical evidence of the existence of a double Griffiths phase when taking into account finite-size effects. The two associated dynamical exponents z increase rapidly as the critical lines are approached, in agreement with the recent conjecture of a divergence at the two transitions in the thermodynamic limit.