2 Figure 2: (color online) (a) Photoemission intensity distribution integrated over [ E$_{F}$ − 5 meV, E$_{F}$ + 5 meV ] window for Fe 1 . 04 (Te 0 . 66 Se 0 . 34 ). (b) The Fermi surfaces are constructed based on the measured Fermi crossings, which are labeled by squares, circles, crosses and triangles for the β , γ , δ and δ ′ bands respectively. (c) The photoemission intensity along the cut #1 in the Γ − M direction, and (d) its second derivative with respect to energy. (e) The data in panel c is repotted after dividing the angle integrated energy distribution curve. (f) The EDC’s for data in panel c. (g) The MDC’s in the box area of panel c. (h) The MDC’s in the box area of panel e. The crosses mark the feature positions based on a double Lorenzian fit.(i) The photoemission intensity along the cut #2 in the Γ − X direction, and (j) its second derivative. Data were taken with circularly polarized 22 eV photons at HSRC. There are also critical differences between the iron- pnictides and iron-chalcogenides, in particular, between their structures of magnetic ordering. A common collinear commensurate antiferromagnetic (AFM) order- ing has been identified in all iron-pnictides. However, the magnetic state of the Fe 1+ $_{y}$Te 1$_{−}$ $_{x}$Se$_{x}$ family has a bi-collinear commensurate or incommensurate antiferro- magnetic ordering depending on the concentration of the interstitial iron [12, 13]. It is still in a heated debate about the origin of magnetic ordering in iron-based su- perconductors. While models based on local moments have been suggested to understand both magnetic order- ings [14–19], the collinear AFM in the iron-pnictides in principle can originate from nesting mechanism between the hole pockets at Γ and the electron pockets at M [20], but the bi-collinear magnetic structure is inconsis- tent with this picture since there is no Fermi surface at X . Is there a connection between the electronic struc- ture and magnetic ordering in the iron-chalcogenides? If there is, what is the connection? The answers of these fundamental questions require a deep understanding of the electronic structures of iron-chalcogenides. However, there is just few data reported on the electronic structure of iron-chalcogenides [21]. the density function theory (DFT) calculations. The orbital characters of individual bands are studied by polarization-dependence studies and found to agree with the calculation as well. No obvious effect of the fluctu- ating SDW is observed on the electronic structure. Fur- thermore, we found that although most aspects of the electronic structure of this iron-chalcogenide are similar to the iron-pnictides, there are clearly three separated bands at the zone center for the iron-chalcogenides, while there appear just two separated features for the normal state of iron-pnictides. Moreover, the symmetry prop- erties of the iron-chalcogenide bands near the zone cen- ter are different from those of the iron-pnictides. The difference and similarity between the iron-pnictides and iron-chalcogenides in their electronic structure may shed light on our understanding of the role of anions and the superconductivity in iron-based superconductors. Fe 1 . 04 (Te 0 . 66 Se 0 . 34 ) single crystal was synthesized with the NaCl/KCl-flux method. Fe powder, Te powder and Se powder were weighed according to the ratio of Fe:Te:Se=1:0.7:0.3 (mole), and pressed into thin plates. Then FeTe(Se) polycrystal was acquired by reacting the plate in an evacuated quartz tube at 1173 K for 24 hours. FeTe(Se) polycrystal and the NaCl/KCl- flux were weighed according to the ratio of FeTe(Se): In this Article, we investigate the electronic structure of Fe 1 . 04 Te 0 . 66 Se 0 . 34 with high resolution angle-resolved photoemission spectroscopy (ARPES) and band calcula- tion. The measured Fermi surfaces and the band struc- ture are identified and found to qualitatively agree with II. MATERIAL AND EXPERIMENTAL SETUP