Abstract
Investigation of the inelastic neutron scattering spectra in Fe1+yTe1-xSex near a signature wave vector Q=(1,0,0) for the bond-order wave (BOW) formation of parent compound Fe1+yTe [D. Fobes, Phys. Rev. Lett. 112, 187202 (2014)PRLTAO0031-900710.1103/PhysRevLett.112.187202] reveals an acoustic-phonon-like dispersion present in all structural phases. While a structural Bragg peak accompanies the mode in the low-temperature phase of Fe1+yTe, it is absent in the high-temperature tetragonal phase, where Bragg scattering at this Q is forbidden by symmetry. Notably, this mode is also observed in superconducting FeTe0.55Se0.45, where structural and magnetic transitions are suppressed, and no BOW has been observed. The presence of this "forbidden" phonon indicates that the lattice symmetry is dynamically or locally broken by magneto-orbital BOW fluctuations, which are strongly coupled to lattice in these materials.
| Original language | English |
|---|---|
| Article number | 121103 |
| Journal | Physical Review B |
| Volume | 94 |
| Issue number | 12 |
| DOIs | |
| State | Published - Sep 1 2016 |
Funding
Work at BNL was supported by Office of Basic Energy Sciences (BES), Division of Materials Sciences and Engineering, U.S. Department of Energy (DOE), under Contract No. DE-SC00112704. Research conducted at ORNL's Spallation Neutron Source and High Flux Isotope Reactor was sponsored by the Scientific User Facilities Division, Office of Basic Energy Sciences, US Department of Energy. We acknowledge the support of the National Institute of Standards and Technology, U.S. Department of Commerce, in providing the neutron research facilities used in this work.