Controllable chirality-induced geometrical Hall effect in the frustrated strongly-correlated metal UCu$_{5}$

A current of electrons traversing a landscape of localized spins possessing non-coplanar magnetic order gains a geometrical (Berry) phase which can lead to a Hall voltage independent of the spin-orbit coupling within the material--a geometrical Hall effect. In this talk, I will present experimental data and Monte-Carlo simulation results showing that the strongly-correlated metal UCu$_{5}$ possesses an unusually large controllable geometrical Hall effect at $T$ \textless\ 1.2K due to its frustration-induced magnetic order. The magnitude of the Hall response exceeds 20{\%} of the $\nu =$1 quantum Hall effect per atomic layer, which translates into an effective magnetic field of several hundred Tesla acting on the electrons. The existence of such a large geometric Hall response in UCu$_{5}$ opens a new field of inquiry into the importance of the role of frustration in highly-correlated electron materials. \textit{B.G. Ueland et al., Nat. Commun. }\textbf{\textit{3}}\textit{, 1067 (2012).}