Ising phases of Heisenberg ladders in a magnetic field.
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.
Penc
Karlo
K
Research Institute for Theoretical Solid State Physics and Optics, H-1525 Budapest, P.O.B. 49, Hungary.
Fouet
Jean-Baptiste
JB
Miyahara
Shin
S
Tchernyshyov
Oleg
O
Mila
Frédéric
F