Related Experiment Video
Updated: Aug 13, 2026

Contrast-Matching Detergent in Small-Angle Neutron Scattering Experiments for Membrane Protein Structural Analysis and Ab Initio Modeling
Published on: October 21, 2018
Critical amplitude ratio of the susceptibility in the random-site two-dimensional Ising model
Lev N Shchur1, Oleg A Vasilyev
1Landau Institute for Theoretical Physics, 142432 Chernogolovka, Russia. lev@itp.ac.ru
Abstract:
We present a different way of probing the universality class of the site-diluted two-dimensional Ising model. We analyze Monte Carlo data for the magnetic susceptibility, introducing a fitting procedure in the critical region applicable even for a single sample with quenched disorder. This gives us the possibility to fit simultaneously the critical exponent, the critical amplitude, and the sample-dependent pseudocritical temperature. The critical amplitude ratio of the magnetic susceptibility is seen to be independent of the concentration q of the empty sites for all investigated values of q < or =0.25. At the same time the average effective exponent gamma(eff) is found to vary with the concentration q, which may be argued to be due to logarithmic corrections to the power law of the pure system. These corrections are canceled in the susceptibility amplitude ratio as predicted by theory. The central charge of the corresponding field theory was computed and compared well with the theoretical predictions.
Related Concept Videos
Atomic Nuclei: Nuclear Spin State Population Distribution
¹H NMR Signal Multiplicity: Splitting Patterns
Interpreting ¹H NMR Signal Splitting: The (n + 1) Rule
Magnetic Susceptibility and Permeability
When diamagnetic materials are placed under an external magnetic field, the moments opposite to the field are induced. Hence, the susceptibility for diamagnets has a minimal negative value of 10-5–10-6. Since...
Wald-Wolfowitz Runs Test II
For binary data, runs are identified using symbols such as + and −, or equivalently, 1s and 0s. In...
Law of Rational Indices

