Bosonic mode interpretation of novel STM and related experimental results, within boson-fermion modelling of HTSC Materials

Abstract

This paper seeks to synthesize much recent work on the HTSC materials around the latest energy resolved scanning tunnelling microscopy (STM) results from Davis and coworkers. The STM conductance diffuse scattering results in particular are employed as point of entry to discuss bosonic modes, both of condensed and uncondensed form. The bosonic mode picture is essential to understanding an ever growing range of observations within the HTSC field. The work is expounded within the context of the site-inhomogeneous negative-U boson-fermion modelling long advocated by the author. This general approach is presently seeing much theoretical development, into which I have looked to couple many of the experimental advances. While this formal theory is not yet sufficiently detailed to cover adequately all the experimental complexities presented by the real cuprate systems, it is clear it affords very appreciable support to the line taken. An attempt is made throughout to clarify why and how it is that these novel circumstances and phenomena are tied so very closely to this particular set of materials.