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arXiv · 1003.0992

Quantum spin metal state on a decorated honeycomb lattice

K. S. Tikhonov·M. V. Feigel'man
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Abstract

We present a modification of exactly solvable spin-(1/2) Kitaev model on the decorated honeycomb lattice, with a ground state of "spin metal" type. The model is diagonalized in terms of Majorana fermions; the latter form a 2D gapless state with a Fermi-circle those size depends on the ratio of exchange couplings. Low-temperature heat capacity C(T) and dynamic spin susceptibility χ(ω,T) are calculated in the case of small Fermi-circle. Whereas C(T)\sim T at low temperatures as it is expected for a Fermi-liquid, spin excitations are gapful and χ(ω,T) demonstrate unusual behaviour with a power-law peak near the resonance frequency. The corresponding exponent as well as the peak shape are calculated.

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K. S. Tikhonov, M. V. Feigel'man. 2010-03-04. Quantum spin metal state on a decorated honeycomb lattice. https://doi.org/10.1103/physrevlett.105.067207

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