We report the magnetic and calorimetric measurements in single crystal samples of the square lattice J1−J2 quantum antiferromagnet BaCdVO(PO4)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∗≃150~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.
@article{arxiv.1807.09549,
title = {Thermodynamics of a frustrated quantum magnet on a square lattice},
author = {K. Yu. Povarov and V. K. Bhartiya and Z. Yan and A. Zheludev},
journal= {arXiv preprint arXiv:1807.09549},
year = {2019}
}