Nematic fluctuations at nonzero q in FeSe vs. Ba(Fe1-xCox)2As2
ORAL
Abstract
FeSe and Ba(Fe1-xCox)2As2 (Ba122) have several shared phase transitions such as the tetragonal-to-orthorhombic structural transition associated with nematic electronic order as well as a superconducting transition. There are also important differences, including magnetic order found in the Ba122 but not the FeSe compounds. Our recent inelastic X-ray and neutron scattering measurements of TA phonons in these compounds focused on anomalies in their dispersion. These anomalies reflect nematic fluctuations at nonzero q. We obtained nematic correlation length as a function of temperature from fits to these anomalous dispersions and found that it is similar in FeSe and Ba(Fe0.96Co0.04)2As2: compounds whose structural transition temperatures are close. In addition, we measured TA phonon dispersions and linewidths in optimally-doped Ba122 in detail. I will discuss the implications of the observed phenomena, focusing on the relation between nematic correlation length and the structural transitions, magnetic order, and superconductivity.
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Presenters
Adrian Merritt
University of Colorado, Boulder
Authors
Adrian Merritt
University of Colorado, Boulder
Frank Weber
Karlsruhe Institute of Technology
John-Paul Castellan
Karlsruhe Institute of Technology
Alfred Q R Baron
RIKEN, SPring-8, RIKEN
Daisuke Ishikawa
RIKEN, SPring-8, JASRI/SPring-8
Ayman Said
Argonne National Laboratory, Argonne Natl Lab, Advanced Photon Source, Argonne National Laboratory
Ahmet Alatas
Argonne National Laboratory, Argonne Natl Lab, Advanced Photon Source, Argonne National Laboratory
Travis Williams
Oak Ridge Natl Lab
Rafael M Fernandes
University of Minnesota, School of Physics and Astronomy, University of Minnesota, Minneapolis, Minnesota 55455, USA., School of Physics and Astronomy, University of Minnesota, Physics, University of Minnesota
Joerg Schmalian
Karlsruhe Institute of Technology, TKM, Karlsruhe Institute of Technology (KIT)
