title: Antiferromagnetic THz-frequency Josephson-like Oscillator Driven by Spin Current.
abstract: The development of compact and tunable room temperature sources of coherent THz-frequency signals would open a way for numerous new applications. The existing approaches to THz-frequency generation based on superconductor Josephson junctions (JJ), free electron lasers, and quantum cascades require cryogenic temperatures or/and complex setups, preventing the miniaturization and wide use of these devices. We demonstrate theoretically that a bi-layer of a heavy metal (Pt) and a bi-axial antiferromagnetic (AFM) dielectric (NiO) can be a source of a coherent THz signal. A spin-current flowing from a DC-current-driven Pt layer and polarized along the hard AFM anisotropy axis excites a non-uniform in time precession of magnetizations sublattices in the AFM, due to the presence of a weak easy-plane AFM anisotropy. The frequency of the AFM oscillations varies in the range of 0.1-2.0 THz with the driving current in the Pt layer from 108A/cm2to 109A/cm2. The THz-frequency signal from the AFM with the amplitude exceeding 1 V/cm is picked up by the inverse spin-Hall effect in Pt. The operation of a room-temperature AFM THz-frequency oscillator is similar to that of a cryogenic JJ oscillator, with the energy of the easy-plane magnetic anisotropy playing the role of the Josephson energy.
authors.affiliation: Department of Physics, Oakland University, 146 Library Drive, Rochester, Michigan, 48309-4479, USA.
authors.forename: Roman
authors.initials: R
authors.lastname: Khymyn
authors.affiliation: Department of Physics, Oakland University, 146 Library Drive, Rochester, Michigan, 48309-4479, USA.|Kotelnikov Institute of Radio-engineering and Electronics of RAS, 11-7 Mokhovaya street, Moscow, 125009, Russia.
authors.forename: Ivan
authors.initials: I
authors.lastname: Lisenkov
authors.affiliation: Department of Physics, Oakland University, 146 Library Drive, Rochester, Michigan, 48309-4479, USA.
authors.forename: Vasyl
authors.initials: V
authors.lastname: Tiberkevich
authors.affiliation: Institute of Magnetism, National Academy of Sciences of Ukraine, Kiev, Ukraine.|National Taras Shevchenko University of Kiev, 03127, Kiev, Ukraine.
authors.forename: Boris A
authors.initials: BA
authors.lastname: Ivanov
authors.affiliation: Department of Physics, Oakland University, 146 Library Drive, Rochester, Michigan, 48309-4479, USA.
authors.forename: Andrei
authors.initials: A
authors.lastname: Slavin