Topological Order Generated by a Random Field in a 2D Exchange Model

Journal Article · 03 July 2018 · Physical Review Letters

DOI: https://doi.org/10.1103/PhysRevLett.121.017201 · OSTI ID:1461459

Chudnovsky, E. M. ^[1]; Garanin, D. A. ^[2]

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1. City Univ. of New York (CUNY), NY (United States); Herbert H. Lehman College and Graduate School, The City University of New York
2. City Univ. of New York (CUNY), NY (United States)

In this paper, we study a 2D exchange model with a weak static random field on lattices containing over $${10}^{8}$$ spins. Ferromagnetic correlations persist on the Imry-Ma scale inversely proportional to the random-field strength and decay exponentially at greater distances. We find that the average energy of the correlated area is close to the ground-state energy of a Skyrmion, while the topological charge of the area is close to ±1. The correlation function of the topological charge density changes sign at a distance determined by the ferromagnetic correlation length, while its Fourier transform exhibits a maximum. Finally, these findings suggest that static randomness transforms a 2D ferromagnetic state into a Skyrmion-anti-Skyrmion glass.

• Research Organization: City Univ. of New York (CUNY), NY (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
• Grant/Contract Number: FG02-93ER45487
• OSTI ID: 1461459
• Journal Information: Physical Review Letters, Journal Name: Physical Review Letters Journal Issue: 1 Vol. 121; ISSN 0031-9007
• Publisher: American Physical Society (APS)Copyright Statement
• Country of Publication: United States
• Language: English