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arXiv · 1807.09549

Thermodynamics of a frustrated quantum magnet on a square lattice

K. Yu. Povarov·V. K. Bhartiya·Z. Yan·A. Zheludev
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Abstract

We report the magnetic and calorimetric measurements in single crystal samples of the square lattice $J_{1}-J_{2}$ quantum antiferromagnet BaCdVO(PO$_4$)$_2$. An investigation of the scaling of magnetization reveals a "dimensionality reduction" indicative of a strong degree of geometric frustration. Below a characteristic temperature of $T^{\ast}\simeq150$~mK we observe the emergence of an additional strongly fluctuating quantum phase close to full magnetic saturation. It is separated from the magnetically ordered state by first- and second-order phase transitions, depending on the orientation of the applied magnetic field. We suggest that this phase may indeed be related to the theoretically predicted spin-nematic state.

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K. Yu. Povarov, V. K. Bhartiya, Z. Yan, A. Zheludev. 2019-01-11. Thermodynamics of a frustrated quantum magnet on a square lattice. https://doi.org/10.1103/physrevb.99.024413

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