“…This is a further strong manifestation in favor of the continuous phase transition scenario. Thus, the evidence presented in this subsection for the 3D bimodal RFIM is in agreement with the favored view of most existing theoretical and numerical studies [17,19,54,57] that the phase transition of the 3D RFIM is of second order. In order to present even stronger numerical evidence of a vanishing (in the limit L → ∞) surface tension we will now attempt to go well beyond the observation of several typical RF realizations.…”
Section: One-r Wl Approach Transition Identification By the Lk Methodssupporting
confidence: 91%
“…Various RF probability distributions, such as the Gaussian, the wide bimodal distribution (with a Gaussian width), and the above bimodal distribution have been considered [17,18,19,20,21,22,23,24,25,26,27,28,29].…”
Abstract. Two numerical strategies based on the Wang-Landau and Lee entropic sampling schemes are implemented to investigate the first-order transition features of the 3D bimodal (±h) random-field Ising model at the strong disorder regime. We consider simple cubic lattices with linear sizes in the range L = 4 − 32 and simulate the system for two values of the disorder strength: h = 2 and h = 2.25. The nature of the transition is elucidated by applying the Lee-Kosterlitz free-energy barrier method. Our results indicate that, despite the strong first-order-like characteristics, the transition remains continuous, in disagreement with the early mean-field theory prediction of a tricritical point at high values of the random-field.
“…This is a further strong manifestation in favor of the continuous phase transition scenario. Thus, the evidence presented in this subsection for the 3D bimodal RFIM is in agreement with the favored view of most existing theoretical and numerical studies [17,19,54,57] that the phase transition of the 3D RFIM is of second order. In order to present even stronger numerical evidence of a vanishing (in the limit L → ∞) surface tension we will now attempt to go well beyond the observation of several typical RF realizations.…”
Section: One-r Wl Approach Transition Identification By the Lk Methodssupporting
confidence: 91%
“…Various RF probability distributions, such as the Gaussian, the wide bimodal distribution (with a Gaussian width), and the above bimodal distribution have been considered [17,18,19,20,21,22,23,24,25,26,27,28,29].…”
Abstract. Two numerical strategies based on the Wang-Landau and Lee entropic sampling schemes are implemented to investigate the first-order transition features of the 3D bimodal (±h) random-field Ising model at the strong disorder regime. We consider simple cubic lattices with linear sizes in the range L = 4 − 32 and simulate the system for two values of the disorder strength: h = 2 and h = 2.25. The nature of the transition is elucidated by applying the Lee-Kosterlitz free-energy barrier method. Our results indicate that, despite the strong first-order-like characteristics, the transition remains continuous, in disagreement with the early mean-field theory prediction of a tricritical point at high values of the random-field.
“…The ground state of the RFIM can be found in polynomial time 13 by efficient combinatorial algorithms so that zero temperature simulations are much faster and allow for much larger system sizes than positive temperature simulations. Critical exponents have been obtained from zero temperature studies 14,15,16 that are mostly consistent with the scaling theories 5,6,7 , series methods 17 and real space renormalization group approaches 18,19,20 .…”
In this paper the three-dimensional random-field Ising model is studied at both zero temperature and positive temperature. Critical exponents are extracted at zero temperature by finite size scaling analysis of large discontinuities in the bond energy. The heat capacity exponent ␣ is found to be near zero. The ground states are determined for a range of external field and disorder strength near the zero temperature critical point and the scaling of ground state tilings of the field-disorder plane is discussed. At positive temperature the specific heat and the susceptibility are obtained using the Wang-Landau algorithm. It is found that sharp peaks are present in these physical quantities for some realizations of systems sized 16 3 and larger. These sharp peaks result from flipping large domains and correspond to large discontinuities in ground state bond energies. Finally, zero temperature and positive temperature spin configurations near the critical line are found to be highly correlated suggesting a strong version of the zero temperature fixed point hypothesis.
“…Ground states are much easier to simulate than thermal states and, according to the zero temperature fixed point hypothesis, the T = 0 and T > 0 transitions are in the same universality class. Critical exponents have been obtained from zero temperature studies that are mostly consistent with the scaling theories [5,6,7], series methods [16] and real space renormalization group approaches [17,18,19].…”
The random field Ising model is studied numerically at both zero and positive temperature. Ground states are mapped out in a region of random field and external field strength. Thermal states and thermodynamic properties are obtained for all temperatures using the Wang-Landau algorithm. The specific heat and susceptibility typically display sharp peaks in the critical region for large systems and strong disorder. These sharp peaks result from large domains flipping. For a given realization of disorder, ground states and thermal states near the critical line are found to be strongly correlated--a concrete manifestation of the zero temperature fixed point scenario.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.