Unusual Charge Localization in Zn-doped and Heavily Underdoped YBa2Cu3O7-d at Low Temperatures

TL;DR

This study investigates the low-temperature normal-state resistivity of Zn-doped and underdoped YBa2Cu3O7-d, revealing a metallic ground state contrary to expectations of divergence, under high magnetic fields.

Contribution

It provides new insights into the charge transport properties of Zn-doped and underdoped YBCO, challenging previous assumptions about insulating behavior at low temperatures.

Findings

Resistivity does not follow log(1/T) behavior.

Normal state tends to be metallic at low temperatures.

Results hold under magnetic fields up to 18 T.

Abstract

The in-plane normal-state resistivity of Zn-doped YBa2Cu3O7-d and heavily underdoped pure YBCO single crystals is measured down to low temperatures under magnetic fields up to 18 T. We found that the temperature dependence of the normal-state rho_ab does not obey log(1/T) and tends not to diverge in the low temperature limit. The result suggests that the ``ground state'' of the normal state of YBCO is metallic.