Determination of pairing symmetry from magnetotunneling spectroscopy: A case study for quasi-one-dimensional organic superconductors

Abstract

We propose that anisotropic p-, d-, or f-wave pairing symmetries can be distinguished from a tunneling spectroscopy in the presence of magnetic fields, which is exemplified here for a model organic superconductor ${(\mathrm{TMTSF})}_{2}X.$ The shape of the Fermi surface (quasi-one-dimensional in this example) affects sensitively the pairing symmetry, which in turn affects the shape (U or V) of the gap along with the presence/absence of the zero-bias peak in the tunneling in a subtle manner. Yet, an application of a magnetic field enables us to identify the symmetry, which is interpreted as an effect of the Doppler shift in Andreev bound states.