Infrared Study of the Spin Reorientation Transition and Its Reversal in the Superconducting State in Underdoped Ba1-xKxFe2As2
| Authors | |
|---|---|
| Year of publication | 2015 |
| Type | Article in Periodical |
| Magazine / Source | PHYSICAL REVIEW LETTERS |
| MU Faculty or unit | |
| Citation | |
| Web | http://journals.aps.org/prl/pdf/10.1103/PhysRevLett.115.027003 |
| Doi | http://dx.doi.org/10.1103/PhysRevLett.115.027003 |
| Field | Solid matter physics and magnetism |
| Keywords | Iron-based superconductors |
| Description | With infrared spectroscopy we investigated the spin-reorientation transition from an orthorhombic antiferromagnetic (o-AF) to a tetragonal AF (t-AF) phase and the reentrance of the o-AF phase in the superconducting state of underdoped Ba1-xKxFe2As2. In agreement with the predicted transition from a single-Q to a double-Q AF structure, we found that a distinct spin density wave develops in the t-AF phase. The pair breaking peak of this spin density wave acquires much more low-energy spectral weight than the one in the o-AF state which indicates that it competes more strongly with superconductivity. We also observed additional phonon modes in the t-AF phase which likely arise from a Brillouin-zone folding that is induced by the double-Q magnetic structure with two Fe sublattices exhibiting different magnitudes of the magnetic moment. |
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