Kirtley Scientific - John R. Kirtley

Angle-resolved phase
sensitive measurements of
the in-plane gap symmetry
in YBa2Cu3O7

We have determined the position of the in-plane nodes in YBCO, and confirmed the small size, if any, of an imaginary component to the gap, by imaging the presence or absence of the half-flux quantum effect in a series of 2-junction YBCO-Nb rings with varying junction angles relative to the YBCO crystalline axes.

"Angle-resolved phase-sensitive determination of the in-plane gap symmetry in YBa2Cu3O7", J. R. Kirtley, C. C. Tsuei, A. Ariando, C. J. M. Verwijs, S. Harkema and H. Hilgenkamp, Nature Physics 2 , 190 (2006).