Double-peak specific heat feature in frustrated antiferromagnetic clusters

Abstract

We study the nature of the double-peak specific heat structure in kagome clusters. That containing 12 spins is considered thoroughly by numerical diagonalization. Simple models are proposed revealing the low-$T$ peak nature at $T_l<\Delta$ ($\Delta$ is the spin gap) in this case and in those of larger clusters studied so far. We show that the rapid increase in density of states just above the spin gap gives rise to this peak. These models establish the reason for the weak magnetic field sensitivity of the low-$T$ peak. Our discussion could be appropriate for other frustrated antiferromagnetic systems too.

7 pages, 3 figures

References in corpus (10)

• Pyrochlore Antiferromagnet: A Three-Dimensional Quantum Spin Liquid
• First excitations of the spin 1/2 Heisenberg antiferromagnet on the kagomé lattice
• Order versus Disorder in the Quantum Heisenberg Antiferromagnet on the Kagom{é} lattice: an approach through exact spectra analysis
• Spin-1/2 Kagome Like Lattice in Volborthite Cu3V2O7(OH)2-H2O
• Spin Liquid in the Multiple-Spin Exchange model on the Triangular lattice: 3He on graphite
• Spin-1/2 Heisenberg-Antiferromagnet on the Kagome Lattice: High Temperature Expansion and Exact Diagonalisation Studies
• Magneto-thermodynamics of the spin-1/2 Kagome antiferromagnet
• Elementary excitations in the $\Delta$-chain
• Hidden long range order in Heisenberg Kagome antiferromagnets
• Chiral Kosterlitz-Thouless transition in the frustrated Heisenberg antiferromagnet on a pyrochlore slab

Cited by in corpus (1)

• Unusual excitations and double-peak specific heat in a bond-alternating spin-$1$ $K$-$\Gamma$ chain