2013/01/05 by Sudip Chakravarty
Physics and Astronomy · #cond-mat.supr-con #cond-mat.str-el
paper · pdf · doi:10.1103/physrevb.89.087101
published as Phys. Rev. B 89, 087101 (2014) · 3.25 pages
arxiv created 2013/01/05 · arxiv updated 2014/02/10
I comment on two recent papers on Kerr effect as evidence of gyrotropic order in cuprates, and I suggest that the arguments may not be sound. The difficulty is that in practically all cases the wave vector kz perpendicular to the copper-oxygen plane is not a good quantum number. This appears to be problematic for arXiv:1212.2698, whereas in arXiv:1212.2274 the symmetry arguments may turn out to be robust, but the microscopic picture is wanting. Thus, the Kerr effect in cuprates remains a puzzle, as there is little doubt that the arguments presented against time reversal symmetry breaking appear to be rather strong in both of these papers on experimental grounds.