Observation of an electron band above the Fermi level in FeTe${}_{0.55}$Se${}_{0.45}$ from \emph{in-situ} surface doping

Abstract

We used \emph{in-situ} potassium (K) evaporation to dope the surface of the iron-based superconductor FeTe${}_{0.55}$Se${}_{0.45}$. The systematic study of the bands near the Fermi level confirms that electrons are doped into the system, allowing us to tune the Fermi level of this material and to access otherwise unoccupied electronic states. In particular, we observe an electron band located above the Fermi level before doping that shares similarities with a small three-dimensional pocket observed in the cousin, heavily-electron-doped KFe${}_{2-x}$Se${}_2$ compound.

4 pages, 3 figures. Figures 1 and 2 modified

References in corpus (7)

• Heavily electron-doped electronic structure and isotropic superconducting gap in AxFe2Se2 (A=K,Cs)
• Bi-collinear antiferromagnetic order in the tetragonal $\alpha$-FeTe
• Strong nodeless pairing on separate electron Fermi surface sheets in (Tl, K)Fe${}_{1.78}$Se${}_2$ probed by ARPES
• Spin waves in the $(\pi ,0)$ magnetically ordered iron chalcogenide Fe${}_{1.05}$Te
• Electron-Hole Asymmetry in Superconductivity of Pnictides Originated from the Observed Rigid Chemical Potential Shift
• Observation of an isotropic superconducting gap at the Brillouin zone center of Tl${}_{0.63}$K${}_{0.37}$Fe${}_{1.78}$Se${}_2$
• A flat band at the chemical potential of a Fe1.03Te0.94S0.06 superconductor observed by angle-resolved photoemission spectroscopy

Cited by in corpus (5)

• Monolayer FeSe on SrTiO${}_3$
• FeTe${}_{0.55}$Se${}_{0.45}$: a multiband superconductor in the clean and dirty limit
• Polarity-dependent charge-density wave in a kagome superconductor CsV3Sb5
• Emergent vortex Majorana zero mode in iron-based superconductors
• Surface valence transition in SmS by alkali metal adsorption