Abstract
We apply a low-field ( G) technique to measure the critical pair momentum in thin underdoped films of and reflecting a wide range of hole doping. We observe that scales with and therefore superfluid density in our two-dimensional cuprate films. This relationship was famously predicted by a universal model of the cuprates with a doping-independent superconducting gap, but has not been observed by high field measurements of the coherence length because high-field cuprate phenomena obscure the simple scaling we observe at much lower fields.
- Received 19 June 2014
- Revised 11 February 2015
DOI:https://doi.org/10.1103/PhysRevB.91.104524
©2015 American Physical Society