paper

Nanoscale phase separation in deep underdoped Bi $_{2}$ Sr $_{2}$ CuO $_{6 + I^´}$ and Ca $_{2}$ CuO $_{2}$ Cl $_{2}$

arXiv:1405.3992 · doi:10.1103/PhysRevB.91.140501

Abstract

We demonstrate that tunneling spectra in deeply underdoped Bi $_{2}$ Sr $_{2}$ CuO $_{6 + I^´}$ (Bi2201) and Ca $_{2}$ CuO $_{2}$ Cl $_{2}$ (CCOC) provide clear evidence for nanoscale phase separation (NPS), causing the gap to fill with doping rather than close. The phase separation extends over a doping range from half filling to approximately $x \sim 0.09$ . Assuming the NPS is in the form of stripes, then the nodal gap -- which we model as a Coulomb gap -- arises from impurity pinning of the charged stripes, ultimately driving a metal-insulator transition.

Nanoscale phase separation in deep underdoped Bi2​Sr2​CuO6+I^´​ and Ca2​CuO2​Cl2​

Abstract

Nanoscale phase separation in deep underdoped Bi $_{2}$ Sr $_{2}$ CuO $_{6 + I^´}$ and Ca $_{2}$ CuO $_{2}$ Cl $_{2}$