An enhanced susceptibility is a natural consequence of the "heavy fermion" (HF) state rendering the possibility of measurably large nonlinear susceptibilities. In recent work a universal behavior of the peaks observed in the linear (\Chi_1) and the third order (\Chi_3) susceptibility in HF metamagnets has been identified. This universality is well accounted for by a single energy scale model considering on-site correlations only. A prediction of this model is a peak in the fifth order susceptibility, \Chi_5, as well. In the first measurements on a HF metamagnet, UPt3 reported herein, we find that Chi_5 rather than attaining a peak, saturates at low temperatures and is positive. The thermodynamic implications of these towards the stability of the metamagnetic HF state are discussed.
@article{arxiv.1403.1970,
title = {Metamagnetism and the Fifth Order Susceptibility in UPt3},
author = {B. S. Shivaram and Brian Dorsey and D. G. Hinks and Pradeep Kumar},
journal= {arXiv preprint arXiv:1403.1970},
year = {2015}
}