Ising phases of Heisenberg ladders in a magnetic field

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Date
2007-09-14
Journal Title
Journal ISSN
Volume Title
Publisher
American Physical Society
Abstract
We show that Dzyaloshinskii-Moriya (DM) interactions can substantially modify the phase diagram of spin-1/2 Heisenberg ladders in a magnetic field provided they compete with exchange. For nonfrustrated ladders, they induce a local magnetization along the DM vector that turns the gapless intermediate phase into an Ising phase with broken translational symmetry, while for frustrated ladders, they extend the Ising order of the half-integer plateau to the surrounding gapless phases of the purely Heisenberg case. Implications for experimental ladder and dimer systems are discussed.
Description
Keywords
Dzyaloshinskii-Moriya interactions, Ising model, Heisenberg model, magnetic field, spin-1/2 Heisenberg ladders, gapless intermediate phase, broken translational symmetry
Citation
Physical Review Letters 14 Sept. 2007, vol.99, no.11, pp. 117201-1-4