Antiferromagnetic order oriented by Fulde-Ferrell-Larkin-Ovchinnikov superconducting order.

Resolving the high-field superconducting phase (HFSP), often called the Q phase, and the antiferromagnetic or spin-density-wave (SDW) order appearing in the phase remains a crucial issue on the superconductor CeCoIn5. It is shown that a switching of the SDW domain due to a tiny change of the magnetic field direction in HFSP, reported and interpreted as evidence of the presence of a π-triplet pairing inducing the SDW order [S. Gerber etal., Nat. Phys. 10, 126 (2014)], can be explained with no triplet pairing component if the d-wave superconducting order in HFSP includes the Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) modulation parallel to the field. This result corroborates the idea that HFSP of CeCoIn5 and the SDW order found only in the phase are consequences of the strong paramagnetic pair breaking in this d-wave superconductor. [ABSTRACT FROM AUTHOR]