title: Microwave soft x-ray microscopy for nanoscale magnetization dynamics in the 5-10 GHz frequency range.
abstract: We present a scanning transmission x-ray microscopy setup combined with a novel microwave synchronization scheme for studying high frequency magnetization dynamics at synchrotron light sources. The sensitivity necessary to detect small changes in the magnetization on short time scales and nanometer spatial dimensions is achieved by combining the excitation mechanism with single photon counting electronics that is locked to the synchrotron operation frequency. Our instrument is capable of creating direct images of dynamical phenomena in the 5-10 GHz range, with high spatial resolution. When used together with circularly polarized x-rays, the above capabilities can be combined to study magnetic phenomena at microwave frequencies, such as ferromagnetic resonance (FMR) and spin waves. We demonstrate the capabilities of our technique by presenting phase resolved images of a ∼6 GHz nanoscale spin wave generated by a spin torque oscillator, as well as the uniform ferromagnetic precession with ∼0.1° amplitude at ∼9 GHz in a micrometer-sized cobalt strip.
authors.affiliation: Department of Physics, Stanford University, Stanford, California 94305, USA.
authors.forename: Stefano
authors.initials: S
authors.lastname: Bonetti
authors.affiliation: Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA.
authors.forename: Roopali
authors.initials: R
authors.lastname: Kukreja
authors.affiliation: Department of Physics, Stanford University, Stanford, California 94305, USA.
authors.forename: Zhao
authors.initials: Z
authors.lastname: Chen
authors.affiliation: Institut für Experimentalphysik, Universität Duisburg-Essen, Duisburg, Germany.
authors.forename: Detlef
authors.initials: D
authors.lastname: Spoddig
authors.affiliation: Institut für Experimentalphysik, Universität Duisburg-Essen, Duisburg, Germany.
authors.forename: Katharina
authors.initials: K
authors.lastname: Ollefs
authors.affiliation: Institut für Experimentalphysik, Universität Duisburg-Essen, Duisburg, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Schöppner
authors.affiliation: Institut für Experimentalphysik, Universität Duisburg-Essen, Duisburg, Germany.
authors.forename: Ralf
authors.initials: R
authors.lastname: Meckenstock
authors.affiliation: Institut für Experimentalphysik, Universität Duisburg-Essen, Duisburg, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Ney
authors.affiliation: Linear Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA.
authors.forename: Jude
authors.initials: J
authors.lastname: Pinto
authors.affiliation: Linear Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA.
authors.forename: Richard
authors.initials: R
authors.lastname: Houanche
authors.affiliation: Linear Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA.
authors.forename: Josef
authors.initials: J
authors.lastname: Frisch
authors.affiliation: Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA.
authors.forename: Joachim
authors.initials: J
authors.lastname: Stöhr
authors.affiliation: Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA.
authors.forename: Hermann A
authors.initials: HA
authors.lastname: Dürr
authors.affiliation: Stanford Synchrotron Radiation Laboratory, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA.
authors.forename: Hendrik
authors.initials: H
authors.lastname: Ohldag