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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]. 

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 

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. 

## II. MATERIAL AND EXPERIMENTAL SETUP 

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): 

