Strain Control of Fermiology and Many-Body Interactions in   Two-Dimensional Ruthenates
  Here we demonstrate how the Fermi surface topology and quantum many-body interactions can be manipulated via epitaxial strain in the spin-triplet superconductor Sr$_2$RuO$_4$ and its isoelectronic counterpart Ba$_2$RuO$_4$ using oxide molecular beam epitaxy (MBE), \emph{in situ} angle-resolved photoemission spectroscopy (ARPES), and transport measurements. Near the topological transition of the $\gamma$ Fermi surface sheet, we observe clear signatures of critical fluctuations, while the quasiparticle mass enhancement is found to increase rapidly and monotonically with increasing Ru-O bond distance. Our work demonstrates the possibilities for using epitaxial strain as a disorder-free means of manipulating emergent properties, many-body interactions, and potentially the superconductivity in correlated materials. 
B. Burganov, C. Adamo, A. Mulder, M. Uchida, P. D. C. King, J. W.   Harter, D. E. Shai, A. S. Gibbs, A. P. Mackenzie, R. Uec...
cond-mat.supr-con cond-mat.mtrl-sci cond-mat.str-el