Comment on Counterintuitive consequence of heating in strongly driven intrinsic junctions of Bi$_2$Sr$_2$CaCu$_2$O$_{8+\delta}$ mesas

TL;DR

This paper critically examines previous claims that self-heating causes conductance peaks at the critical temperature in Bi-2212 mesas, showing that these claims are invalid for various sizes and configurations of mesas.

Contribution

The paper refutes prior conclusions about heating effects in Bi-2212 mesas, demonstrating that the earlier extrapolations to smaller, well-thermally anchored mesas are incorrect.

Findings

Previous data do not support heating-induced conductance peaks at T_c

Extrapolations to small, well-anchored mesas are invalid

Identifies inconsistencies and misleading references in prior work

Abstract

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.