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arXiv · 1009.0053

Quantum fluctuations and strong mass renormalization in NiCl2-4SC(NH2)2

Y. Kohama·A. Sologubenko·N. R. Dilley·V. S. Zapf·M. Jaime·J. Mydosh·A. Paduan-Filho·K. Al-Hassanieh·P. Sengupta·S. Gangadharaiah·A. L. Chernyshev·C. D. Batista
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Abstract

In a number of quantum paramagnets, magnetic field can induce a quantum phase transition to an antiferromagnetic state which exists for a range of fields Hc1 < H < Hc2. Generally, these compounds exhibit a significant asymmetry in their properties at low- and high-field transitions. Here we present detailed specific heat and thermal conductivity measurements in NiCl2-4SC(NH2)2 together with analytical and numerical results. We show that the asymmetry is caused by a strong renormalization of the effective mass of spin excitations due to quantum fluctuations for H<Hc1 that are absent for H<Hc2.

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Y. Kohama, A. Sologubenko, N. R. Dilley, V. S. Zapf, M. Jaime, J. Mydosh, A. Paduan-Filho, K. Al-Hassanieh, P. Sengupta, S. Gangadharaiah, A. L. Chernyshev, C. D. Batista. 2010-12-03. Quantum fluctuations and strong mass renormalization in NiCl2-4SC(NH2)2. https://doi.org/10.1103/physrevlett.106.037203

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