Electron/hole liquids in highTcsuperconductors and easy paths for supercarriers through the vibrational lattice

In a recent study in this Journal, of manifestly BCS body-centred-cubic transition metals, we presented a picture of easy paths for the supercarriers (Cooper pairs) based on electron-lattice properties. Turning to high T c cuprates, it has been advocated for a long time that phonons play only a minor role. That point of view is challenged here by appealing first to fairly recent experiments on the oxygen isotope effects in the CuO2 planes of high T c materials and secondly to measurements on the enhancement of T c by epitaxial strain. Again, we advocate easy paths for supercarriers to travel through the vibrating lattice in a high T c family as consistent with these quite different experiments. However, these arguments apply to for such a family such that , which is the maximum T c within a family, depends importantly on anti-ferromagnetic spin fluctuations. But, we expect the variation of within such a family to correlate with easy paths for supercarriers to travel through the vibrating lattice