Thermal expansion of the spin-1/2 Heisenberg-chain compound Cu(C$_4$H$_4$N$_2$)(NO$_3$)$_2$

J. Rohrkamp; M. D. Phillips; M. M. Turnbull; T. Lorenz

doi:10.1088/1742-6596/200/1/012169

paper

Thermal expansion of the spin-1/2 Heisenberg-chain compound Cu(C $_{4}$ H $_{4}$ N $_{2}$ )(NO $_{3}$ ) $_{2}$

arXiv:0907.0400 · doi:10.1088/1742-6596/200/1/012169

Abstract

Compounds containing magnetic subsystems representing simple model spin systems with weak magnetic coupling constants are ideal candidates to test theoretical predictions for the generic behavior close to quantum phase transitions. We present measurements of the thermal expansion and magnetostriction of the spin-1/2-chain compound copper pyrazine dinitrate Cu(C $_{4}$ H $_{4}$ N $_{2}$ )(NO $_{3}$ ) $_{2}$ . Of particular interest is the low-temperature thermal expansion close to the saturation field $H_{c} ≃ 13.9 T$ , which defines a quantum phase transition from the gapless Luttinger liquid state to the fully saturated state with a finite excitation gap. We observe a sign change of the thermal expansion for the different ground states, and at the quantum critical point $H_{c}$ the low-temperature expansion approaches a $1/ T$ divergence. Thus, our data agree very well with the expected quantum critical behaviour.

4 pages, 3 figures; to appear in the proceedings of the ICM 09 held in Karlsruhe, Germany

Thermal expansion of the spin-1/2 Heisenberg-chain compound Cu(C $_{4}$ H $_{4}$ N $_{2}$ )(NO $_{3}$ ) $_{2}$

Abstract

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Thermal expansion of the spin-1/2 Heisenberg-chain compound Cu(C4​H4​N2​)(NO3​)2​

Abstract

References in corpus (7)

Cited by in corpus (7)

Thermal expansion of the spin-1/2 Heisenberg-chain compound Cu(C $_{4}$ H $_{4}$ N $_{2}$ )(NO $_{3}$ ) $_{2}$