Fermi surface reconstruction in (BaK)FeAs (0.44 1) probed by thermoelectric power measurements
arXiv preprint arXiv:1405.4306, 2014•arxiv.org
We report in-plane thermoelectric power measurements on single crystals of (Ba $ _ {1-x} $
K $ _x $) Fe $ _2 $ As $ _2 $(0.44$\leq x\leq $1). We observe a minimum in the S $| _ {T=
const} $ versus x at x~ 0.55 that can be associated with the change in the topology of the
Fermi surface, a Lifshitz transition, related to the electron pockets at the center of M point
crossing the Fermi level. This feature is clearly observable below~ 75 K. Thermoelectric
power also shows a change in the x~ 0.8-0.9 range, where maximum in the thermoelectric …
K $ _x $) Fe $ _2 $ As $ _2 $(0.44$\leq x\leq $1). We observe a minimum in the S $| _ {T=
const} $ versus x at x~ 0.55 that can be associated with the change in the topology of the
Fermi surface, a Lifshitz transition, related to the electron pockets at the center of M point
crossing the Fermi level. This feature is clearly observable below~ 75 K. Thermoelectric
power also shows a change in the x~ 0.8-0.9 range, where maximum in the thermoelectric …
We report in-plane thermoelectric power measurements on single crystals of (BaK)FeAs (0.44 1). We observe a minimum in the S versus x at x ~ 0.55 that can be associated with the change in the topology of the Fermi surface, a Lifshitz transition, related to the electron pockets at the center of M point crossing the Fermi level. This feature is clearly observable below ~ 75 K. Thermoelectric power also shows a change in the x ~ 0.8 - 0.9 range, where maximum in the thermoelectric power collapses into a plateau. This Lifshitz transition is most likely related to the reconstruction of the Fermi surface associated with the transformation of the hole pockets at the M point into four blades as observed by ARPES measurements.
arxiv.org