Fermi surface topology and low-lying quasiparticle dynamics of parent Fe₁₊ₓTe/Se Superconductor by orbital-polarization resolved ARPES

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We report the first photoemission study of Fe₁₊ₓTe - the host compound of the newly discovered iron-chalcogenide superconductors (maximum Tc 27K). Our results reveal a pair of nearly electron-hole compensated Fermi pockets, strong Fermi velocity renormalization and an absence of a spin-density-wave gap. A shadow hole pocket is observed at the X-point of the Brillouin zone which is consistent with a long-range ordered magneto-structural groundstate. No signature of Fermi surface nesting instability associated with Q=(π/2, π/2) is observed. Our results collectively reveal that the Fe₁₊ₓTe series is dramatically different from the high Tc pnictides and likely harbor unusual mechanism for superconductivity and magnetic order.