The structure of the superconducting order parameter in the iron-pnictide superconductor BaFe2(As0.67P0.33)2 (Tc=31 K) with line nodes is studied by the angle-resolved thermal conductivity measurements in a magnetic field rotated within the basal plane. We find that the thermal conductivity displays distinct fourfold oscillations with minima when the field is directed at ±45 with respect to the tetragonal a axis. We discuss possible gap structures that can account for the data, and conclude that the observed results are most consistent with the closed nodal loops located at the flat parts of the electron Fermi surface with high Fermi velocity. © 2011 American Physical Society.
Publication Source (Journal or Book title)
Physical Review B - Condensed Matter and Materials Physics
Yamashita, M., Senshu, Y., Shibauchi, T., Kasahara, S., Hashimoto, K., Watanabe, D., Ikeda, H., Terashima, T., Vekhter, I., Vorontsov, A., & Matsuda, Y. (2011). Nodal gap structure of superconducting BaFe2(As 1-xPx)2 from angle-resolved thermal conductivity in a magnetic field. Physical Review B - Condensed Matter and Materials Physics, 84 (6) https://doi.org/10.1103/PhysRevB.84.060507