Isolated ferromagnetic bonds in the two-dimensional anisotropic spin-1/2 Heisenberg antiferromagnet

Journal Article · Sat Aug 01 04:00:00 EDT 1992 · Physical Review, B: Condensed Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.46.3135· OSTI ID:7293428

Haas, S; Duffy, D; Schlottmann, P ^[1]

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1. Department of Physics and Center for Materials Research and Technology, Florida State University, Tallahassee, Florida 32306 (United States)

An isolated ferromagnetic bond of coupling constants {ital K}{sub {ital z}} and {ital K}{sub {ital x}{ital y}} replacing an antiferromagnetic link in the spin-1/2 anisotropic Heisenberg antiferromagnet of coupling constants {ital J}{sub {ital z}}{ge}{ital J}{sub {ital x}{ital y}} on a square lattice is investigated within the linearized spin-wave approximation. Two competing interactions affect the local ordered magnetic moment {l angle}{ital S}{sub {ital i}}{sup {ital z}}{r angle} and the correlation {l angle}{ital S}{sub {ital i}}{sup {ital x}S}{sub {ital j}}{sup {ital x}}{r angle}: The longitudinal terms {ital J}{sub {ital z}} tend to enhance the sublattice magnetization, while the transverse terms {ital J}{sub {ital x}{ital y}} represent the quantum fluctuations that suppress the long-range order. We analyze the interplay between these two effects as a function of {ital K}{sub {ital z}} and {ital K}{sub {ital x}{ital y}} at the impurity link. The linearized spin-wave approximation breaks down for sufficiently large {ital K}{sub {ital z}} and {ital K}{sub {ital x}{ital y}} as a consequence of the frustration of the two plaquettes adjacent to the ferromagnetic bond.

• DOE Contract Number: FG05-91ER45443
• OSTI ID: 7293428
• Journal Information: Physical Review, B: Condensed Matter; (United States), Journal Name: Physical Review, B: Condensed Matter; (United States) Vol. 46:5; ISSN 0163-1829; ISSN PRBMD
• Country of Publication: United States
• Language: English

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FERMIONS
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