Anisotropic superconductivity in La(O,F)BiSeS crystals revealed by   field-angle dependent Andreev reflection spectroscopy
  From field-angle dependent Andreev reflection spectroscopy on single crystals of La(O,F)BiSeS, which belongs to the recently discovered BiCh 2 (Ch = S, Se) based layered superconductors, we found that the superconductivity in La(O,F)BiSeS is highly anisotropic. We measured a superconducting energy gap of 0.61 meV for current injected along c-axis at 1.5 K. Detailed temperature and magnetic field dependent studies of the gap also reveal the presence of unconventional pairing in La(O,F)BiSeS. We show that the observed anisotropic superconducting properties can be attributed to the anisotropy in the superconducting order parameter with a complex symmetry in superconducting La(O,F)BiSeS. 
Mohammad Aslam, Sirshendu Gayen, Avtar Singh, Masashi Tanaka, Takuma   Yamaki, Yoshihiko Takano and Goutam Sheet
cond-mat.supr-con