English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

We consider theoretically the effects of an applied uniform magnetic field onthe magnetic spectrum of anisotropic two-dimensional and Dzyaloshinskii-Moriyalayered quantum Heisenberg antiferromagnets. The first case is relevant forsystems such as the two-dimensional square lattice antiferromagnetSr(2)CuO(2)Cl(2), while the later is known to be relevant to the physics of thelayered orthorhombic antiferromagnet La(2)CuO(4). We first establish thecorrespondence betwenn the low-energy spectrum obtained within the anisotropicnon-linear sigma model and by means of the spin-wave approximation for astandard easy-axis antiferromagent. Then, we focus on the field-theory approachto calculate the magnetic field dependence of the magnon gaps and spectralintensities for magnetic fields applied along the three possiblecrystallographic directions. We discuss the various possible ground states andtheir evolution with temperature for the different field orientations, and theoccurrence of spin-flop transitions for fields perpendicular to the layers(transverse fields) as well as for fields along the easy axis (longitudinalfields). Measurements of the one-magnon Raman spectrum in Sr(2)CuO(2)Cl(2) andLa(2)CuO(4) and a comparison between the experimental results and thepredictions of the present theory will be reported in part II of this researchwork [L. Benfatto et al., cond-mat/0602664].Comment: 21 pages, 11 figures, final version. Part II of the present work is  presented in cond-mat/060266

Field dependence of the magnetic spectrum in anisotropic and Dzyaloshinskii-Moriya antiferromagnets. I. Theory