Evidence of a critical hole concentration in underdoped YBa${}_2$Cu${}_3$O${}_y$ single crystals revealed by ${}^{63}$Cu NMR

S. -H. Baek, T. Loew, V. Hinkov +4

We report a ${}^{63}$Cu NMR investigation in detwinned YBa${}_2$Cu${}_3$O${}_y$ single crystals, focusing on the highly underdoped regime (y=6.35-6.6). Measurements of both the spectra and…