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Title: Spin–spin correlation length in a two-dimensional frustrated magnet and its relation to doping

In a spherically symmetric self-consistent approach (SSSA), the spin-1/2 J{sub 1}–J{sub 2} Heisenberg model on a two-dimensional square lattice is considered for two-time retarded spin–spin Green’s functions. The spin excitation spectrum, ω(q), and spin gaps at symmetric points are obtained for the entire J{sub 1}–J{sub 2} diagram, i.e., for any ϕ, J{sub 1} = cosϕ, and J{sub 2} = sinϕ. The structure factor c{sub q} and the correlation length ξ at finite temperature are calculated in the entire range of parameters. A radical difference in the behavior of the system in the upper, frustrated (0 ⩽ ϕ ⩽ π), and the lower, nonfrustrated (π ⩽ ϕ ⩽ 2π), regions of the diagram is demonstrated. In the latter region, there is a first-order phase transition that is unique on the phase diagram. For a weakly frustrated antiferromagnet (J{sub 1} > J{sub 2} > 0), the results obtained are compared with the experimental dependence of ξ on temperature and doping level. A correspondence rule is proposed between frustration in a spin model and the doping of an antiferromagnet with holes.
Authors:
 [1] ; ;  [2] ;  [1]
  1. Russian Academy of Sciences, Institute for High Pressure Physics (Russian Federation)
  2. Moscow Institute of Physics and Technology (State University) (Russian Federation)
Publication Date:
OSTI Identifier:
22472077
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Experimental and Theoretical Physics; Journal Volume: 121; Journal Issue: 3; Other Information: Copyright (c) 2015 Pleiades Publishing, Inc.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ANTIFERROELECTRIC MATERIALS; COMPARATIVE EVALUATIONS; CORRELATIONS; EXCITATION; GREEN FUNCTION; HOLES; MAGNETS; PHASE DIAGRAMS; PHASE TRANSFORMATIONS; SPHERICAL CONFIGURATION; SPIN; STRUCTURE FACTORS; TETRAGONAL LATTICES; TWO-DIMENSIONAL SYSTEMS