Leggett modes and multiband superconductivity in Sr2RuO4

Sr2RuO4 is a prototypical multiband superconductor with three bands crossing the Fermi level. These bands exhibit distinct dimensional characteristics, with one quasi-2D γ band and two quasi-1D α and β bands. This leads to the expectation that the superconductivity on the γ band may be only weakly Josephson-coupled to that on the other two bands. Based on an explicit microscopic weak coupling calculation appropriate for Sr2RuO4, we study the …