Yu, RongSi, Qimiao2016-04-052016-04-052013Yu, Rong and Si, Qimiao. "Orbital-Selective Mott Phase in Multiorbital Models for Alkaline Iron Selenides K1−xFe2−ySe2." <i>Physical Review Letters,</i> 110, no. 14 (2013) American Physical Society: 146402. http://dx.doi.org/10.1103/PhysRevLett.110.146402.https://hdl.handle.net/1911/88857We study a multiorbital model for the alkaline iron selenides K1−xFe2−ySe2 using a slave-spin method. With or without ordered vacancies, we identify a metal-to-Mott-insulator transition at the commensurate filling of six 3d electrons per iron ion. For Hund’s couplings beyond a threshold value, this occurs via an intermediate orbital-selective Mott phase, in which the 3d xy orbital is Mott localized while the other 3d orbitals remain itinerant. This phase is still stabilized over a range of carrier dopings. Our results lead to an overall phase diagram for the alkaline iron selenides, which provides a unified framework to understand the interplay between the strength of the vacancy order and carrier doping. In this phase diagram, the orbital-selective Mott phase provides a natural link between the superconducting K1−xFe2−ySe2 and its Mott-insulating parent compound.engArticle is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.Journal articlehttp://dx.doi.org/10.1103/PhysRevLett.110.146402