Metamagnetic Nematic Phase of Sr$_{3}$Ru$_{2}$O$_{7}$

In this talk I will review our group's recent observations that a quantum phase with pronounced electrical transport anisotropies forms in the vicinity of a metamagnetic quantum critical point in Sr$_{3}$Ru$_{2}$O$_{7}$. The behaviour, which is strongly dependent on disorder and is only seen in the highest purity crystals, has phenomenological similarities with prior observations on two-dimensional electron gases in semiconductor devices [1,2]. Its appearance in bulk in Sr$_{3}$Ru$_{2}$O$_{7}$ has allowed us to perform a number of thermodynamic measurements, and also offers the promise of study using modern surface-based spectroscopies such as angle resolved photoemission and spectroscopic imaging scanning tunneling microscopy. References [1] For example M.P. Lilly \textit{et al.}, Phys. Rev. Lett. \textbf{82}, 394 (1999); ibid \textbf{83}, 824 (1999) [2] W. Pan \textit{et al}., Phys. Rev. Lett. \textbf{83}, 820 (1999). Collaborators: S.A. Grigera$^{1}$, R.A. Borzi$^{1,2}$, A. Rost$^{1}$, J.F. Mercure$^{1}$, J. Farrell$^{1}$, R.S. Perry$^{3}$, A.G. Green$^{1}$, M. Allan$^{1}$, M. Wang$^{4}$, J. Lee$^{1}$, F. Baumberger$^{1}$, S.J.S Lister$^{1}$, S.L. Lee$^{1}$, J.C.S. Davis$^{1,4}$, Z.X. Shen$^{5}$, Y. Maeno$^{6}$. $^{1}$ University of St Andrews, Scotland $^{2 }$INFTA, La Plata, Argentina $^{3}$ University of Edinburgh, Scotland $^{4 }$Cornell University, USA $^{5}$ Stanford University, USA $^{6}$ Kyoto University, Japan