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arXiv · 1411.4764

Quantum degradation of the second order phase transition

S. M. Stishov·A. E. Petrova·S. Yu. Gavrilkin·L. A. Klinkova
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Abstract

The specific heat, magnetization and thermal expansion of single crystals of antiferromagnetic insulator EuTe, measured at temperatures down to 2 K and in magnetic fields up to 90 kOe, demonstrate non trivial properties. The Neel temperature, being 9.8 K at H=0, decreases with magnetic field and tends to zero at 76 kOe, therefore forming a quantum critical point. The heat capacity and thermal expansion coefficient reveal lambda-type anomalies at the second order magnetic phase transition at low magnetic fields, evolving to simple jumps at high magnetic fields and low temperatures, well described in a fluctuation free mean-field theory. The experimental data and the corresponding analysis favor the quantum concept of effective increasing space dimensionality at low temperatures that suppresses a fluctuation divergence at a second order phase transition.

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S. M. Stishov, A. E. Petrova, S. Yu. Gavrilkin, L. A. Klinkova. 2014-11-18. Quantum degradation of the second order phase transition. https://doi.org/10.1103/physrevb.91.144416

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