In a recent paper [Phys.Rev.B 81, 224518 (2010)], C. Kurter et al, analyzed the effect of strong self-heating in large-area Bi$_2$Sr$_2$CaCu$_2$O$_{ 8+\delta}$ (Bi-2212) mesa structures. They conclude that $dI/dV$ conductance peaks in their mesas occur when mesas are heated to the superconducting critical temperature $T_c$. Further on they extrapolate this statement for all mesas, including much smaller and much better thermally anchored mesas used in Intrinsic Tunnelling Spectroscopy (ITS). Here I show that their conclusion does not hold neither for previously reported data, nor even for their own mesas; the very remote extrapolation to ITS is invalid. I also point out a number of inconsistencies and misleading references.
Categories: cond-mat.supr-con