Spin-flop transitions and spin-wave gaps in La_2CuO_4

Abstract

We study the spin-wave spectrum and the spin-flop transitions in La_2CuO_4 in a uniform magnetic field at zero temperature. Using the non-linear sigma-model, we show that a field applied along the orthorhombic b direction leads to a two-step rotation of the staggered magnetization, first in the bc and then in the ac plane, until the order parameter is completely aligned along the c axis. In contrast, for a perpendicular magnetic field, we find a conventional spin-flop transition induced by the competition between the field and the interlayer coupling. A comparison with recent measurements of the field-dependence of the in-plane spin-wave gap shows a beautiful agreement between theory and experiments.

7 pages, 3 figures; added reference

References in corpus (9)

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• One-magnon Raman scattering in La(2)CuO(4): the origin of the field-induced mode
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Cited by in corpus (4)

• Negative Hopping Magnetoresistance and Dimensional Crossover in Lightly Doped Cuprate Superconductors
• Impurity susceptibility and the fate of spin-flop transitions in lightly-doped La(2)CuO(4)
• Quantum corrections to the spin-wave spectrum of La${}_2$CuO${}_4$ in an external magnetic field
• AC Hopping Magnetotransport Across the Spin Flop Transition in Lightly Doped La_2CuO_4