Publications


Oscillatory energy exchange between waves coupled by a dynamic artificial crystal.

Phys Rev Lett 108 (2012) 015505-

AD Karenowska, JF Gregg, VS Tiberkevich, AN Slavin, AV Chumak, AA Serga, B Hillebrands

We describe a general mechanism of controllable energy exchange between waves propagating in a dynamic artificial crystal. We show that if a spatial periodicity is temporarily imposed on the transmission properties of a wave-carrying medium while a wave is inside, this wave is coupled to a secondary counterpropagating wave and energy oscillates between the two. The oscillation frequency is determined by the width of the spectral band gap created by the periodicity and the frequency difference between the coupled waves. The effect is demonstrated with spin waves in a dynamic magnonic crystal.


Oscillatory Energy Exchange between Waves Coupled by a Dynamic Artificial Crystal

PHYSICAL REVIEW LETTERS 108 (2012) ARTN 015505

AD Karenowska, JF Gregg, VS Tiberkevich, AN Slavin, AV Chumak, AA Serga, B Hillebrands


Mechanical oscillator

(2012) US13/144886

A Karenowska, JF Gregg


Delay-line self-oscillator

(2011) US/13144878

A Karenowska, JF Gregg


Temporal evolution of inverse spin Hall effect voltage in a magnetic insulator-nonmagnetic metal structure

Applied Physics Letters 99 (2011) 182512

A Karenowska, MB Jungfleisch, AV Chumak, VI Vasyuchka, AA Serga, B Obry, H Schultheiss, PA Beck, E Saitoh, B Hillebrands


Employing magnonic crystals to dictate the characteristics of auto-oscillatory spin-wave systems

Journal of Physics: Conference Series 303 (2011)

AD Karenowska, AV Chumak, AA Serga, JF Gregg, B Hillebrands

Spin-wave active rings - positive-feedback systems incorporating spin-wave waveguides - provide important insight into fundamental magnetics, enable experimental investigations into nonlinear wave phenomena, and potentially find application in microwave electronics. Such rings break into spontaneous, monomode oscillation at a certain threshold value of feedback gain. In general, the wavenumber of this initially excited, threshold mode is impossible to predict precisely. Here we discuss how, by exploiting resonant spin-wave reflections from a magnonic crystal, an active ring system having a threshold mode with a well-defined and precisely predictable wavenumber may be realized. Our work suggests that study and development of active ring systems incorporating magnonic crystals may deliver useful insight into spin-wave transmission in structured magnetic films as well as devices with technological applicability.


Spin information transfer and transport in hybrid spinmechatronic structures

Journal of Physics: Conference Series 303 (2011)

AD Karenowska, JF Gregg, AV Chumak, AA Serga, B Hillebrands

Spin waves have long been recognized as potential signal carriers in spintronic devices. However, practical development of spin wave based information platforms is its infancy. To date, work in this area has focused on one-dimensional topologies based on purely magnetic thin-film transmission systems, typically exploiting interference phenomena to perform logical operations. In this paper, we describe an alternative approach in which spinmechatronic structures combining spin-wave transmission systems with magnetically loaded micro- and nano-mechanical elements provide spin-information processing functionality.


Employing magnonic crystals to dictate the characteristics of auto-oscillatory spin-wave system

JOINT EUROPEAN MAGNETIC SYMPOSIA (JEMS) 303 (2011)

AD Karenowska, AV Chumak, AA Serga, JF Gregg, B Hillebrands


Spin information transfer and transport in hybrid spinmechatronic structures

JOINT EUROPEAN MAGNETIC SYMPOSIA (JEMS) 303 (2011)

AD Karenowska, JF Gregg, AV Chumak, AA Serga, B Hillebrands


Acoustic oscillator

(2011) US13/144888

A Karenowska, JF Gregg, C-C Coussios


Remote sensor device

(2011) US13/144880

A Karenowska


All-linear time reversal by a dynamic artificial crystal

Nature Communications 1 (2010)

AV Chumak, VS Tiberkevich, AD Karenowska, AA Serga, JF Gregg, AN Slavin, B Hillebrands

The time reversal of pulsed signals or propagating wave packets has long been recognized to have profound scientific and technological significance. Until now, all experimentally verified time-reversal mechanisms have been reliant upon nonlinear phenomena such as four-wave mixing. In this paper, we report the experimental realization of all-linear time reversal. The time-reversal mechanism we propose is based on the dynamic control of an artificial crystal structure, and is demonstrated in a spin-wave system using a dynamic magnonic crystal. The crystal is switched from an homogeneous state to one in which its properties vary with spatial period a, while a propagating wave packet is inside. As a result, a linear coupling between wave components with wave vectors k≈π/a and k'=k-2π/a≈-π/a is produced, which leads to spectral inversion, and thus to the formation of a time-reversed wave packet. The reversal mechanism is entirely general and so applicable to artificial crystal systems of any physical nature. © 2010 Macmillan Publishers Limited. All rights reserved.


All-linear time reversal by a dynamic artificial crystal

NATURE COMMUNICATIONS 1 (2010) ARTN 141

AV Chumak, VS Tiberkevich, AD Karenowska, AA Serga, JF Gregg, AN Slavin, B Hillebrands


Magnonic crystal based forced dominant wavenumber selection in a spin-wave active ring

APPLIED PHYSICS LETTERS 96 (2010) ARTN 082505

AD Karenowska, AV Chumak, AA Serga, JF Gregg, B Hillebrands


Rotor blade sensor

(2010) US12/0678036

A Karenowska, JF Gregg


Mechanical oscillator

(2010) PCT/GB2010/000061

A Karenowska, JF Gregg


Acoustic oscillator

(2010) PCT/GB2010/000069

A Karenowska, JF Gregg, C-C Coussios


Remote sensor device

(2010) PCT/GB2010/000065

A Karenowska, JF Gregg


Delay-line self-oscillator

(2010) PCT/GB2010/000068

A Karenowska, JF Gregg


Electromagnetic field-based position sensor

(2009) Granted

A Karenowska, JF Gregg

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