title: Spin pumping and spin-transfer torques in antiferromagnets.
abstract: Spin pumping and spin-transfer torques are two reciprocal phenomena widely studied in ferromagnetic materials. However, pumping from antiferromagnets and its relation to current-induced torques have not been explored. By calculating how electrons scatter off a normal metal-antiferromagnetic interface, we derive pumped spin and staggered spin currents in terms of the staggered field, the magnetization, and their rates of change. For both compensated and uncompensated interfaces, spin pumping is of a similar magnitude as in ferromagnets with a direction controlled by the polarization of the driving microwave. The pumped currents are connected to current-induced torques via Onsager reciprocity relations.
authors.affiliation: Department of Physics, University of Texas at Austin, Austin, Texas 78712, USA.
authors.forename: Ran
authors.initials: R
authors.lastname: Cheng
authors.affiliation: Department of Physics and State Key Laboratory of Surface Physics, Fudan University, Shanghai 200433, China.
authors.forename: Jiang
authors.initials: J
authors.lastname: Xiao
authors.affiliation: Department of Physics, University of Texas at Austin, Austin, Texas 78712, USA and International Center for Quantum Materials, and Collaborative Innovation Center of Quantum Matter, School of Physics, Peking University, Beijing 100871, China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Niu
authors.affiliation: Department of Physics, Norwegian University of Science and Technology, NO-7491 Trondheim, Norway.
authors.forename: Arne
authors.initials: A
authors.lastname: Brataas