title: Engineering the interlayer exchange coupling in magnetic trilayers.
abstract: When the thickness of metal film approaches the nanoscale, itinerant carriers resonate between its boundaries and form quantum well states (QWSs), which are crucial to account for the film's electrical, transport and magnetic properties. Besides the classic origin of particle-in-a-box, the QWSs are also susceptible to the crystal structures that affect the quantum resonance. Here we investigate the QWSs and the magnetic interlayer exchange coupling (IEC) in the Fe/Ag/Fe (001) trilayer from first-principles calculations. We find that the carriers at the Brillouin-zone center (belly) and edge (neck) separately form electron- and hole-like QWSs that give rise to an oscillatory feature for the IEC as a function of the Ag-layer thickness with long and short periods. Since the QWS formation sensitively depends on boundary conditions, one can switch between these two IEC periods by changing the Fe-layer thickness. These features, which also occur in the magnetic trilayers with other noble-metal spacers, open a new degree of freedom to engineer the IEC in magnetoresistance devices.
authors.affiliation: Research Center for Applied Sciences, Academia Sinica, Taipei 11529, Taiwan.
authors.forename: Ching-Hao
authors.initials: CH
authors.lastname: Chang
authors.affiliation: Research Center for Applied Sciences, Academia Sinica, Taipei 11529, Taiwan.
authors.forename: Kun-Peng
authors.initials: KP
authors.lastname: Dou
authors.affiliation: Research Center for Applied Sciences, Academia Sinica, Taipei 11529, Taiwan.
authors.forename: Ying-Chin
authors.initials: YC
authors.lastname: Chen
authors.affiliation: Department of Physics, National Tsing Hua University, Hsinchu 30013, Taiwan.
authors.forename: Tzay-Ming
authors.initials: TM
authors.lastname: Hong
authors.affiliation: Research Center for Applied Sciences, Academia Sinica, Taipei 11529, Taiwan.|Department of Physics, National Tsing Hua University, Hsinchu 30013, Taiwan.
authors.forename: Chao-Cheng
authors.initials: CC
authors.lastname: Kaun