title: Diverging thermal expansion of the spin-ladder system (C5H12N)2CuBr4.
abstract: We present high-resolution measurements of the c(*)-axis thermal expansion and magnetostriction of piperidinium copper bromide (C5H12N)2CuBr4. The experimental data at low temperatures are well accounted for by a two-leg spin-ladder Hamiltonian. The thermal expansion shows a complex behavior with various sign changes and approaches a 1/square root T divergence at the critical fields. All low-temperature features are semiquantitatively explained within a free-fermion model; full quantitative agreement is obtained with quantum Monte Carlo simulations.
authors: II. Physikalisches Institut, Universität zu Köln, Zülpicher Strasse 77, 50937 Köln, Germany. lorenz@ph2.uni-koeln.de
authors: T
authors: T
authors: Lorenz
authors: O
authors: O
authors: Heyer
authors: M
authors: M
authors: Garst
authors: F
authors: F
authors: Anfuso
authors: A
authors: A
authors: Rosch
authors: Ch
authors: Ch
authors: Rüegg
authors: K
authors: K
authors: Krämer