Two-magnon instabilities and other surprises in magnetized quantum antiferromagnets
نویسندگان
چکیده
The ordered states of a planar antiferromagnet with a triangular lattice are investigated in the presence of a magnetic field. The spin wave free energy is taken into account and proves to be important for determining the properties of the system. The phase diagram is constructed. It contains four different phases with rigorous long-range order. Three of them are characterised by different configurations of mean magnetic moments for the three sublattices. The existence of one more non-trivial phase with an algebraic decay of the correlation functions is very probable.
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