Competition between quantum criticality and Fermi liquid behavior revealed by transport measurements in ultrapure Sr$_{3}$Ru$_{2}$O$_{7}$

The layered perovskite metal Sr$_{3}$Ru$_{2}$O$_{7}$ has gained considerable interest since the discovery of its field-tuned quantum criticality [1] and the subsequent discovery of a new electronic phase with a high magnetoresistive anisotropy, consistent with the existence of an electronic nematic fluid [2]. Further studies have explored the properties of the ``normal state'' from which the anisotropic phase emerges in terms of thermodynamics [3] and quantum oscillations [4], but a comprehensive study of the transport properties of the purest samples has so far been lacking. Here, we present the first study of the normal state resistivity of ultrapure Sr$_{3}$Ru$_{2}$O$_{7}$, involving temperature control over more than two orders of magnitude and a 15T magnet system. The high signal to noise of this measurement allows for precise extraction of the temperature dependence exponent and provides detailed understanding of the transport signatures of field-tuned quantum criticality. \newline [1] S. A. Grigera {\it et al}., Science {\bf 294}, 329 (2001). \newline [2] R. A. Borzi {\it et al}., Science {\bf 315}, 214 (2007). \newline [3] A. W. Rost {\it et al}., Science {\bf 325}, 5946 (2009). \newline [4] J.-F. Mercure {\it et al}., Phys. Rev. B {\bf 81}, 235103 (2010).