Absolute values of the London penetration depth in YBa2Cu3O6+y measured by zero field ESR spectroscopy on Gd doped single crystals

T. Pereg-Barnea, P. J. Turner, R. Harris +6

Zero-field electron spin resonance (ESR) of dilute Gd ions substituted for Y in the cuprate superconductor YBa${}_2$Cu${}_3$O${}_{6+\mathrm{y}}$ is used as a novel technique for measuring the…