Comment on “Conductivity of Underdoped ${\mathrm{Y}\mathrm{B}\mathrm{a}}_2{\mathrm{C}\mathrm{u}}_3{\mathrm{O}}_{7-\delta }$: Evidence for Incoherent Pair Correlations in the Pseudogap Regime”

A Comment on the Letter by B. Leridon et al., Phys. Rev. Lett. 87, 197007 (2001). The authors of the Letter offer a Reply.

Figure 1

The open circles are the $\rho \mathrm{\text{−}}T$ curve of ${\mathrm{Y}\mathrm{B}\mathrm{a}}_2{\mathrm{C}\mathrm{u}}_3{\mathrm{O}}_{6.54}$. The dashed and dotted lines are the linear term $(aT+b)$ and VRH term, respectively. The solid line is the sum of both (the first term of the model in 1).