Abstract
The origin of the superconducting state in the recently discovered Fe-based materials is the subject of intense scrutiny. Neutron scattering and NMR (ref.8) measurements have already demonstrated a strong correlation between magnetism and superconductivity. A central unanswered question concerns the nature of the normal-state spin fluctuations that may be responsible for the pairing. Here we present inelastic neutron scattering measurements from large single crystals of superconducting and non-superconducting Fe 1+y Te 1-x Se x . These measurements indicate a spin fluctuation spectrum dominated by two-dimensional incommensurate excitations extending to energies greater than 250 meV. Most importantly, the spin excitations in Fe 1+y Te 1-x Se x have four-fold symmetry about the (1, 0) wavevector (square-lattice (π, π) point). Moreover, the excitations are described by the identical wavevector and can be characterized by the same model as the normal-state spin excitations in the high-T C cuprates. These results demonstrate commonality between the magnetism in these classes of materials, which perhaps extends to a common origin for superconductivity.
Original language | English |
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Pages (from-to) | 182-186 |
Number of pages | 5 |
Journal | Nature Physics |
Volume | 6 |
Issue number | 3 |
DOIs | |
State | Published - Mar 2010 |