3 Figure 3: (color online) (a, b, c) Photoemission data taken with 22 eV circularly polarized photons at HSRC along three momentum cuts as indicated in the Brillouin zone sketch. (d, e, f) Second derivative with respect to energy for data in panels a, b, c respectively. (g, h, i) Momentum distribution curves near E$_{F}$ for data in panels a, b, c respectively. Figure 4: (color online) (a, b, c) Photoemission data taken with 22 eV light at HSRC, and 50 eV, and 100 eV circularly polarized light at SLS respectively. All three momentum cuts cross the Γ -Z line ( k$_{x}$ =0, k$_{y}$ =0, k$_{z}$ ) in the reciprocal space. (d, e, f) Second derivative with respect to energy for data in panels a, b, c respectively. (g, h, i) Momentum distribution curves near E$_{F}$ for data in panels a, b, c respectively. (j, k, l) Energy distribution curves for data in panels a, b, c respec- tively after divided by the Fermi-Dirac distribution function. NaCl/KCl=1:10 (mass). They were thoroughly grounded into a mixture, and loaded into an evacuated quartz tube. The tube was kept at 1223 K for 24 hours and then slowly cooled to 873 K in 100 hours. Finally the quartz tube was cooled in the furnace after shutting off the power. Fe 1 . 04 (Te 0 . 66 Se 0 . 34 ) single crystal was obtained after dis- solving the flux in deionized water. The element com- positions of this single crystal were determined through energy-dispersive x-ray (EDX) analysis with dense sam- pling spots across a 0.4$_{×}$0.4 mm 2 surface area. The EDX result shows that the sample is homogeneous, and the maximal deviation of its compsitions is within 1.8%. The temperature dependence of the magnetic suscepti- bility (Fig. 1) does not show any signs of SDW or struc- tural transition. The resistivity data indicate that crystal reaches the zero resistance at about 9 K. However, the susceptibility measurements show that although regions of the sample become superconducting at 9 K, it reaches a bulk superconducting state at 2 K, with a transition width less than 3 K (10$_{%}$-90$_{%}$). This indicates that the bulk of the single crystal is quite homogeneous. With 1 T magnetic field, superconductivity is suppressed, and there is no sign of field-induced meta-magnetic transition. The photoemission data have been taken with Scienta R4000 electron analyzers at Beamline 9 of Hiroshima syn- chrotron radiation center (HSRC) and the Surface and Interface Spectroscopy (SIS) Beamline of Swiss Light Source (SLS). The typical angular resolution is 0.3 de- gree, and the typical energy resolution is 15 meV. The sample was cleaved in situ , and measured under ultra- high-vacuum better than$_{5}$$_{×}$$_{10}$ $_{−}$11 torr . The sample ag- ing effects are carefully monitored to ensure they do not cause artifacts in our analyses and conclusions. The SIS beamline is equipped with an elliptically polarized undu- lator (EPU), which could switch the photon polarization between horizontal, vertical, or circular mode. This facil- itates the polarization dependence studies, which is use- ful in determining the orbital characters of the bands [22]. The photoemission intensities distribution of Fe 1 . 04 (Te 0 . 66 Se 0 . 34 ) at the Fermi energy is shown in Fig. 2(a). The data were taken at 15 K with 22 eV photons. Similar to the iron-pnictides, the spectral III. BAND STRUCTURE AND FERMI SURFACE