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Search Publications by: Justin Shaw (Fed)

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Displaying 26 - 50 of 80

Observation of spin-orbit effects with spin rotation symmetry

October 13, 2017
Author(s)
Alisha Humphries, Tao Wang, Eric R. Edwards, Shane Allen, Justin Shaw, Hans Nembach, John Xiao, Thomas J. Silva
The spin-orbit interaction in a nonmagnetic/magnetic multilayer has been intensively studied due to its efficient conversion between a spin current and a charge current. In the spin Hall/Rashba-Edelstein effects (SHE/REE) and inverse spin Hall/Rashba

Stoner vs. Heisenberg: Ultrafast exchange reduction and magnon generation during laser-induced demagnetization

December 28, 2016
Author(s)
Thomas J. Silva, Hans T. Nembach, Justin M. Shaw, Emrah Turgut, Dmitriy Zusin, Dominik Legut, Karel Carva, Ronny Knut, Cong Chen, Zhensheng Tao, Stefan Mathias, Martin Aeschlimann, Peter Oppeneer, Henry Kapteyn, Margaret Murnane, Patrik Grychtol
Understanding how the electronic band structure of a ferromagnetic material is modified during laser-induced demagnetization on femtosecond timescales has been a long-standing question in condensed matter physics. Here, we use ultrafast high harmonics to

Anomalously low magnetic damping of a metallic ferromagnet

May 16, 2016
Author(s)
Justin M. Shaw, Martin Schoen, Danny Thonig, Michael L. Schneider, Thomas J. Silva, Hans T. Nembach, Olle Eriksson, Olof Karis
The phenomenology of magnetic damping is of critical importance to devices which seek to exploit the electronic spin degree of freedom since damping strongly affects the energy required and speed at which a device can operate. However, theory has struggled

Non-collinear generation of angularly isolated circularly polarized high harmonics

September 21, 2015
Author(s)
Justin M. Shaw, Daniel Hickstein, Franklin Dollar, Patrik Grychtol, Jennifer Ellis, Carlos Hernandez-Garcia, Ronny J. Knut, Christian Gentry, Henry Kapteyn, Margaret Murnane
We generate ultrashort pulses of angularly isolated, circularly polarized extreme ultraviolet (EUV) light through the first implementation of noncollinear high harmonic generation with circularly polarized driving lasers. The noncollinear geometry offers

Higher order perpendicular magnetic anisotropy in ultra-thin Co60Fe20B20 layers and the observation of an easy cone state.

June 1, 2015
Author(s)
Justin M. Shaw, Hans T. Nembach, Mathias A. Weiler, Martin A. Schoen, Thomas J. Silva, Jonathan Z. Sun, Daniel C. Worledge
We used broadband ferromagnetic resonance (FMR) spectroscopy to measure the second and forth order perpendicular magnetic anisotropies in Ta/ Co60Fe20B20/MgO layers over a thickness range of 0.8-5 nm. For a thickness greater than 1.0 nm, the easy axis is

Terbium-Doped Magnetite Nanocrystals for Multimodal Imaging Agents

May 1, 2015
Author(s)
Katherine P. Rice, Stephen E. Russek, Roy H. Geiss, Justin M. Shaw, Robert J. Usselman, Eric R. Evarts, Thomas J. Silva, Hans T. Nembach, Elke Arenholz, Yves Idzerda
High quality cubic Tb-doped magnetite nanocrystals have been fabricated and have shown that the Tb is incorporated into the octahedral 3+ sites. Magnetization and FMR data indicate that the Tb spins are weakly coupled to the iron spin lattice at room

Nondestructive measurement of the evolution of layer-specific mechanical properties in sub-10nm bilayer films

April 21, 2015
Author(s)
Justin M. Shaw, Kathleen Hoogeboom-Pot, Jorge Hernandez-Charpak, Henry Kapteyn, Margaret Murnane, Damiano Nardi
ABSTRACT: We use short-wavelength extreme-ultraviolet light to independently measure the mechanical properties of disparate layers within a bilayer film with single-monolayer sensitivity. We show that in Ni/Ta nanostructured systems, while their densities

Temperature-dependent structure of Tb-doped magnetite nanoparticles

February 13, 2015
Author(s)
Katherine P. Rice, Stephen E. Russek, Roy H. Geiss, Justin Shaw, Robert J. Usselman, Eric R. Evarts, Thomas J. Silva, Hans Nembach, Elke Arenholz, Yves U. Idzerda
High quality 5 nm cubic Tb-doped magnetite nanoparticles have been synthesized by a modified wet-chemical method to investigate tailoring of magnetic properties for imaging and biomedical applications. We show that the Tb is incorporated into the

Generation of bright phase-matched circularly-polarized extreme ultraviolet high harmonics

December 8, 2014
Author(s)
Justin M. Shaw, Patrik Grychtol, Dmitriy Zusin, Ronny J. Knut, Tenio Popmintchev, Hans T. Nembach, Avner Fleischer, Henry Kapteyn, Margaret Murnane, Ofer Kfir, Oren Cohen
Circularly-polarized extreme UV and X-ray radiation provides valuable access to the structural, electronic and magnetic properties of materials. To date, this capability was available only at large-scale X-ray free-electron lasers or synchrotrons. Here we

Phase-Sensitive Detection of Spin Pumping via the ac Inverse Spin Hall Effect

October 6, 2014
Author(s)
Thomas J. Silva, Justin M. Shaw, Hans T. Nembach, Mathias A. Weiler
Sources of pure spin currents are a fundamental building block of spintronic devices. In ferromagnet/normal metal heterostructures, spin currents are generated at ferromagnetic resonance. This is known as spin pumping, where spin currents of both dc and ac

Head and Media Challenges for 3 Tb/in 2 Microwave Assisted Magnetic Recording

February 3, 2014
Author(s)
Thomas J. Silva, Justin M. Shaw, Hans T. Nembach, Mike Mallary, Kumar Srinivasan, Gerado Bertero, Dan Wolf, Christian Kaiser, Michael Chaplin, Mahendra Pakala, Leng Qunwen, Yiming Wang, Carl Elliot, Lui Francis
A specific design for Microwave Assisted Magnetic Recording (MAMR) at about 3Tb/in 2 (0.47 Tb/cm 2 or 4.7 Pb/m 2) is discussed in detail to highlight the challenges of MAMR and to contrast its requirements with conventional Perpendicular Magnetic Recording

Generalized Tabletop EUV Coherent Diffractive Imaging in a Transmission Geometry

September 11, 2013
Author(s)
Justin M. Shaw, Bosheng Zhang, Matthew Seaberg, Daniel Adams, Dennis Gardner, Elizabeth Shanblatt, Henry C. Kapteyn, Margaret M. Murnane
We demonstrate the first generalized tabletop EUV coherent microscope that can image extended, non-isolated, non-periodic, objects. By implementing keyhole coherent diffraction imaging with curved mirrors and a tabletop high harmonic source, we demonstrate

Reply to "Comment on: 'Ultrafast Demagnetization Measurements Using Extreme Ultraviolet Light: Comparison of Electronic and Magnetic Contributions'"

September 4, 2013
Author(s)
Justin Shaw, Thomas J. Silva, Hans Nembach, Emrah Turgut, Patrik Grychtol, Chan La-O-Vorakiat, Henry C. Kapteyn, Margaret M. Murnane, Stefan Mathias, Martin Aeschlimann, Claus Schneider, Daniel E. Adams
In the following, we show that the conclusions of our article titled "Ultrafast Demagnetization Measurements Using Extreme Ultraviolet Light: Comparison of Electronic and Magnetic Contributions" are correct. The Comment of Vodungbo et al. argues that a

Giant Secondary Grain Growth in Cu Films on Sapphire

August 1, 2013
Author(s)
David L. Miller, Mark W. Keller, Justin Shaw, Katherine P. Rice, Robert Keller, Kyle M. Diederichsen
Single crystal metal films on insulating substrates are attractive for microelectronics and other applications, but they are difficult to achieve on macroscopic length scales. The conventional approach to obtaining such films is epitaxial growth at high