Abstract
In the hole-doped -wave cuprate superconductors, due to the midgap surface state (MSS), a zero-bias conductance peak (ZBCP) is widely observed in [110] interface point-contact spectroscopy (PCS). However, a ZBCP of this geometry is rarely observed in the electron-doped cuprates, even though their pairing symmetry is still likely of the wave type. We argue that this is due to the coexistence of antiferromagnetic (AF) and superconducting orders. Generalizing the Blonder-Tinkham-Klapwijk formula to include an AF coupling, it is shown explicitly that the MSS is destroyed by the AF order. The calculated PCS is in good agreement with the experiments.
- Received 9 August 2007
DOI:https://doi.org/10.1103/PhysRevB.76.220504
©2007 American Physical Society