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arXiv · 0711.1510

Diverging thermal expansion of the spin-ladder system (C$_5$H$_{12}$N)$_2$CuBr$_4$

T. Lorenz·O. Heyer·M. Garst·F. Anfuso·A. Rosch·Ch. Ruegg·K. Kraemer
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Abstract

We present high-resolution measurements of the $c^\star$-axis thermal expansion and magnetostriction of piperidinium copper bromide \hp. The experimental data at low temperatures is well accounted for by a two-leg spin-ladder Hamiltonian. The thermal expansion shows a complex behaviour with various sign changes and approaches a $1/\sqrt{T}$ divergence at the critical fields. All low-temperature features are semi-quantitatively explained within a free fermion model; full quantitative agreement is obtained with Quantum Monte Carlo simulations.

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T. Lorenz, O. Heyer, M. Garst, F. Anfuso, A. Rosch, Ch. Ruegg, K. Kraemer. 2008-01-07. Diverging thermal expansion of the spin-ladder system (C$_5$H$_{12}$N)$_2$CuBr$_4$. https://doi.org/10.1103/physrevlett.100.067208

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