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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Phase diagram of a frustrated Heisenberg model: From disorder to order and back again

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Miranda, Michel M. J. [1, 2, 3, 4] ; Almeida, Igor C. [2] ; Andrade, Eric C. [2] ; Hoyos, Jose A. [2]
Total Authors: 4
[1] Tech Univ Dresden, Inst Theoret Phys, D-01062 Dresden - Germany
[2] Univ Sao Paulo, Inst Fis Sao Carlos, CP 369, BR-13560970 Sao Carlos, SP - Brazil
[3] Max Planck Inst Chem Phys Fester Stoffe, Nothnitzer Str 40, D-01187 Dresden - Germany
[4] Tech Univ Dresden, Wurzburg Dresden Cluster Excellence Ct Qmat, D-01062 Dresden - Germany
Total Affiliations: 4
Document type: Journal article
Source: Physical Review B; v. 104, n. 5 AUG 4 2021.
Web of Science Citations: 0

We study the effects of bond and site disorder in the classical J(1)-J(2) Heisenberg model on a square lattice in the order-by-disorder frustrated regime 2J(2) > vertical bar J(1)vertical bar. Combining symmetry arguments, numerical energy minimization, and large-scale Monte Carlo simulations, we establish that the finite-temperature Ising-type transition of the clean system is destroyed in the presence of any finite concentration of impurities. We explain this finding via a random-field mechanism which generically emerges in systems where disorder locally breaks the same real-space symmetry spontaneously globally broken by the associated order parameter. We also determine that the phase replacing the clean one is a paramagnet polarized in the nematic glass order with nontrivial magnetic response. This is because disorder also induces noncollinear spin-vortex-crystal order and produces a conjugated transverse dipolar random field. As a result of these many competing effects, the associated magnetic susceptibilities are nonmonotonic functions of the temperature. As a further application of our methods, we show the generation of random axes in other frustrated magnets with broken SU(2) symmetry. We also discuss the generality of our findings and their relevance to experiments. (AU)

FAPESP's process: 19/17026-9 - Frustrated magnets: anisotropy and and inhomogeneities
Grantee:Eric de Castro e Andrade
Support type: Regular Research Grants
FAPESP's process: 19/17645-0 - Magnetic excitations in inhomogeneous frustrated magnets
Grantee:Igor César de Almeida
Support type: Scholarships in Brazil - Doctorate
FAPESP's process: 15/23849-7 - Quantum spin chains
Grantee:Francisco Castilho Alcaraz
Support type: Research Projects - Thematic Grants
FAPESP's process: 16/10826-1 - Multi-user equipment approved in grant 2015/23849-7: computer cluster
Grantee:Francisco Castilho Alcaraz
Support type: Multi-user Equipment Program