The tunneling spectra of YBa(2)Cu(3)O(7-delta) break junctions have been investigated for tunneling close to the node direction. The behavior of the zero-bias conductance peak (ZBCP) and the Josephson current have been studied as a function of the temperature and magnetic field. The deep splitting of the ZBCP is observed starting at T(S)< 20-30 K in agreement with the d(x)(2)-y(2)+/- is order parameter theory [Y. Tanuma, Y. Tanaka, S. Kashiwaya, Phys. Rev. B 64, 214519 (2001)]. We have observed that a low (0.04 T) magnetic field significantly suppresses such splitting. The 1/T temperature dependence of the maximum Josephson current going to saturation at T < T(S) also confirms mixed order parameter formation.
Evidence of s-wave subdominant order parameter in YBa(2)Cu(3)O(7-delta) from break-junction tunneling spectra
BOBBA, Fabrizio;PIANO, SAMANTA;CUCOLO, Anna Maria
2010-01-01
Abstract
The tunneling spectra of YBa(2)Cu(3)O(7-delta) break junctions have been investigated for tunneling close to the node direction. The behavior of the zero-bias conductance peak (ZBCP) and the Josephson current have been studied as a function of the temperature and magnetic field. The deep splitting of the ZBCP is observed starting at T(S)< 20-30 K in agreement with the d(x)(2)-y(2)+/- is order parameter theory [Y. Tanuma, Y. Tanaka, S. Kashiwaya, Phys. Rev. B 64, 214519 (2001)]. We have observed that a low (0.04 T) magnetic field significantly suppresses such splitting. The 1/T temperature dependence of the maximum Josephson current going to saturation at T < T(S) also confirms mixed order parameter formation.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
