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

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 نشر من قبل Thomas Lorenz
 تاريخ النشر 2008
  مجال البحث فيزياء
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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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