# Superaging and Subaging Phenomena in a Nonequilibrium Critical Behavior of the Structurally Disordered Two-Dimensional XY Model

## Abstract

A Monte Carlo numerical simulation of the specific features of nonequilibrium critical behavior is carried out for the two-dimensional structurally disordered XY model during its evolution from a low-temperature initial state. On the basis of the analysis of the two-time dependence of autocorrelation functions and dynamic susceptibility for systems with spin concentrations of p = 1.0, 0.9, and 0.6, aging phenomena characterized by a slowing down of the relaxation system with increasing waiting time and the violation of the fluctuation–dissipation theorem (FDT) are revealed. The values of the universal limiting fluctuation–dissipation ratio (FDR) are obtained for the systems considered. As a result of the analysis of the two-time scaling dependence for spin–spin and connected spin autocorrelation functions, it is found that structural defects lead to subaging phenomena in the behavior of the spin–spin autocorrelation function and superaging phenomena in the behavior of the connected spin autocorrelation function.

- Authors:

- Omsk State University (Russian Federation)

- Publication Date:

- OSTI Identifier:
- 22749978

- Resource Type:
- Journal Article

- Journal Name:
- Journal of Experimental and Theoretical Physics

- Additional Journal Information:
- Journal Volume: 126; Journal Issue: 3; Other Information: Copyright (c) 2018 Pleiades Publishing, Inc.; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 1063-7761

- Country of Publication:
- United States

- Language:
- English

- Subject:
- 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; COMPUTERIZED SIMULATION; CORRELATIONS; MATHEMATICAL EVOLUTION; MONTE CARLO METHOD; SPIN; TWO-DIMENSIONAL CALCULATIONS; TWO-DIMENSIONAL SYSTEMS

### Citation Formats

```
Prudnikov, V. V., E-mail: prudnikv@univer.omsk.su, Prudnikov, P. V., and Popov, I. S.
```*Superaging and Subaging Phenomena in a Nonequilibrium Critical Behavior of the Structurally Disordered Two-Dimensional XY Model*. United States: N. p., 2018.
Web. doi:10.1134/S1063776118020140.

```
Prudnikov, V. V., E-mail: prudnikv@univer.omsk.su, Prudnikov, P. V., & Popov, I. S.
```*Superaging and Subaging Phenomena in a Nonequilibrium Critical Behavior of the Structurally Disordered Two-Dimensional XY Model*. United States. doi:10.1134/S1063776118020140.

```
Prudnikov, V. V., E-mail: prudnikv@univer.omsk.su, Prudnikov, P. V., and Popov, I. S. Thu .
"Superaging and Subaging Phenomena in a Nonequilibrium Critical Behavior of the Structurally Disordered Two-Dimensional XY Model". United States. doi:10.1134/S1063776118020140.
```

```
@article{osti_22749978,
```

title = {Superaging and Subaging Phenomena in a Nonequilibrium Critical Behavior of the Structurally Disordered Two-Dimensional XY Model},

author = {Prudnikov, V. V., E-mail: prudnikv@univer.omsk.su and Prudnikov, P. V. and Popov, I. S.},

abstractNote = {A Monte Carlo numerical simulation of the specific features of nonequilibrium critical behavior is carried out for the two-dimensional structurally disordered XY model during its evolution from a low-temperature initial state. On the basis of the analysis of the two-time dependence of autocorrelation functions and dynamic susceptibility for systems with spin concentrations of p = 1.0, 0.9, and 0.6, aging phenomena characterized by a slowing down of the relaxation system with increasing waiting time and the violation of the fluctuation–dissipation theorem (FDT) are revealed. The values of the universal limiting fluctuation–dissipation ratio (FDR) are obtained for the systems considered. As a result of the analysis of the two-time scaling dependence for spin–spin and connected spin autocorrelation functions, it is found that structural defects lead to subaging phenomena in the behavior of the spin–spin autocorrelation function and superaging phenomena in the behavior of the connected spin autocorrelation function.},

doi = {10.1134/S1063776118020140},

journal = {Journal of Experimental and Theoretical Physics},

issn = {1063-7761},

number = 3,

volume = 126,

place = {United States},

year = {2018},

month = {3}

}