ISSN:
1089-7550
Source:
AIP Digital Archive
Topics:
Physics
Notes:
The ground state of the spin-1/2 nearest-neighbor Heisenberg quantum antiferromagnet on the Kagomé lattice probably lacks spin order; therefore, conventional spin-wave analysis breaks down. To ascertain the ground state, we instead use a systematic 1/n expansion with SU(n) fermions. Two distinct states occur in the large-n limit, depending on the size of the biquadratic interaction J˜. When J˜=0, there are an infinite number of degenerate ground states consisting of disconnected dimers. At finite n, however, this degeneracy is broken by local resonance. In contrast, a globally resonating chiral spin-liquid phase with no spin-Peierls modulation is the likely large-n ground state at sufficiently large J˜. For intermediate values of J˜, a phase transition from the dimer state to the chiral phase occurs as the temperature increases. At a higher temperature, there is a second transition to a paramagnetic state. We comment on the possibility that these phases are experimentally realized by the nuclear magnetic moments of a second layer of 3He atoms lying on a graphite surface.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.347830
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