Figure 7
Measurement of the acoustic (a), = 5 meV, and optic (b), = 24 meV, phonons in FeTe0.55Se0.45. The HYSPEC instrument at SNS was used with two different detector positions. Panels (c) and (d) show the same data as in panels (a) and (b), respectively, symmetrized using the fourfold symmetry of the tetragonal crystal lattice. |