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Digital Library

of the European Council for Modelling and Simulation

 

Title:

Massive Degeneracy and Anomalous Thermodynamics in a Highly Frustrated Ising Model on Honeycomb Lattice

Authors:

Milan Žukovič

Published in:

 

 

(2022). ECMS 2022, 36th Proceedings
Edited by: Ibrahim A. Hameed, Agus Hasan, Saleh Abdel-Afou Alaliyat, European Council for Modelling and Simulation.

 

DOI: http://doi.org/10.7148/2022

ISSN: 2522-2422 (ONLINE)

ISSN: 2522-2414 (PRINT)

ISSN: 2522-2430 (CD-ROM)

 

ISBN: 978-3-937436-77-7
ISBN: 978-3-937436-76-0(CD)

 

Communications of the ECMS , Volume 36, Issue 1, June 2022,

Ålesund, Norway May 30th - June 3rd, 2022

 

Citation format:

Milan Žukovič (2022). Massive Degeneracy and Anomalous Thermodynamics in a Highly Frustrated Ising Model on Honeycomb Lattice, ECMS 2022 Proceedings Edited By: Ibrahim A. Hameed, Agus Hasan, Saleh Abdel-Afou Alaliyat, European Council for Modeling and Simulation.

doi:10.7148/2022-0336

DOI:

https://doi.org/10.7148/2022-0336

Abstract:

We numerically study a prototypical frustrated Ising model on a honeycomb lattice with competing nearest- and second-nearest-neighbor antiferromagnetic interactions, J<sub>1</sub> and J<sub>2</sub>, for the highly frustrated case of J<sub>1</sub> = J<sub>2</sub>. We employ both standard (SMC) and a more sophisticated replica exchange (REMC) Monte Carlo simulations in effort to demonstrate the difficulties of using the former and advantages of using the latter approaches. The ground state of the system is highly degenerate and consists of frozen superantiferromagnetic (SAF) domains, separated by zero-energy domain walls (ZEDW), thus showing no conventional long-range ordering. We demonstrate that such states are difficult to access by using SMC due to complex multimodal energy landscape, characteristic for such systems. On the other hand, the REMC approach turns out to be more efficient in exploring it and thus reaching also states not accessible to SMC. At finite temperatures, the system shows a peculiar behavior with multiple anomalies in thermodynamic functions, which can be attributed to the transitions between several states with the SAF-like ordering characterized by different types of ZEDW.<br>.

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