Theoretical Sciences Unit's online Seminar

Seminar on Critical Aspects of the Three-Dimensional Random-Field Systems

Speaker: Dr. Manoj Kumar

Affiliation: Chemnitz University of Technology, Germany

Date: 30th March 2022 (Wednesday)

Time: 11:00 AM

Venue: Online Meeting

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Abstract

In this talk, I will present the critical behavior of the three-dimensional random-field Ising model (RFIM) and random-field Potts model (RFPM) via determining the ground states at temperature T = 0. While the ground-state problem for the RFIM can be solved exactly, the RFPM problem for more than two states is known to be NP-hard. Hence, an efficient exact algorithm is extremely unlikely to exist.

Using a computationally efficient graph-cut method, we solve the ground state problem for RFPM approximately in polynomial time. A comprehensive study is carried out to predict the critical behavior for the case of 3-state RFPM with the help of approximate ground-state calculations.

In particular, we explored the quantities like magnetization, Binder-cumulant, specific-heat, and susceptibility, and extrapolated them to their quasi-exact solutions. These solutions are used to (precisely) locate the critical point and to calculate (accurately) the critical exponents by performing the finite-size scaling analysis.