Local tunneling probe of (110) Y_0.95Ca_0.05Ba_2Cu_3O_7-delta thin films in a magnetic field

Abstract

Scanning tunneling spectroscopy was performed on (110)-oriented thin films of Ca-overdoped Y${}_{0.95}$Ca${}_{0.05}$Ba${}_2$Cu${}_3$O${}_{7-\delta }$ at 4.2K, to probe the local evolution of Andreev$-$Saint-James surface states in a c-axis magnetic field. In zero field, we observed conductance spectra with spontaneously-split peaks and spectra with unsplit zero-bias peaks. The former showed enhanced splitting with field, and the latter showed threshold splitting above finite fields. Although both field evolutions can be described in terms of screening and orbital supercurrents, within the framework of $d\pm i\alpha$ pairing ($d$=$d_{x^2-y^2}$; $\alpha$=$d_{xy}$,$s$), the enhanced splitting is consistent with only the $d$ + $i\alpha$ state. Our results have direct implications on the stability of broken time-reversal symmetry in cuprate superconductors.

4 pages, 4 figures

References in corpus (9)

• High Resolution Polar Kerr Effect Measurements of Sr2RuO4: Evidence for Broken Time Reversal Symmetry in the Superconducting State
• Andreev - Saint James reflections: a probe of cuprate superconductors
• Robust dx2-y2 pairing symmetry in high-temperature superconductors
• Order parameter node removal in the d-wave superconductor $YB{a}_{2}C{u}_3{O}_{7-x}$ under magnetic field
• Chirality sensitive effect on surface states in chiral p-wave superconductors
• Transition from a mixed to a pure d-wave symmetry in superconducting optimally doped YBa${}_2$Cu${}_3$O${}_{7-x}$ thin films under applied fields
• Tunneling Spectroscopy on c-axis Y{1-x}Ca{x}Ba2Cu3O{7-delta} Thin Films
• Suppression of low-energy Andreev states by a supercurrent in YBa_2Cu_3O_7-delta
• Field Induced Nodal Order Parameter in the Tunneling Spectrum of YBa${}_2$Cu${}_3$O${}_{7-x}$ Superconductor

Cited by in corpus (4)

• Long range proximity effect in La2/3Ca1/3MnO3 (LCMO)/(100)YBa2Cu3O7-delta (YBCO) ferromagnet/superconductor bilayers: Evidence for induced triplet superconductivity in the ferromagnet
• Probing Majorana-like states in quantum dots and quantum rings
• The vortex core excitation spectrum in gapped topological d-wave superconductors
• Self-consistent theory of current injection into $d$ and $d+is$ superconductors