Magnonic charge pumping via spin-orbit coupling.
The interplay between spin, charge and orbital degrees of freedom has led to the development of spintronic devices such as spin-torque oscillators and spin-transfer torque magnetic random-access memories. In this development, spin pumping represents a convenient way to electrically detect magnetization dynamics. The effect originates from direct conversion of low-energy quantized spin waves in the magnet, known as magnons, into a flow of spins from the precessing magnet to adjacent leads. In this case, a secondary spin-charge conversion element, such as heavy metals with large spin Hall angle or multilayer layouts, is required to convert the spin current into a charge signal. Here, we report the experimental observation of charge pumping in which a precessing ferromagnet pumps a charge current, demonstrating direct conversion of magnons into high-frequency currents via the relativistic spin-orbit interaction. The generated electric current, unlike spin currents generated by spin-pumping, can be directly detected without the need of any additional spin-charge conversion mechanism. The charge-pumping phenomenon is generic and gives a deeper understanding of its reciprocal effect, the spin orbit torque, which is currently attracting interest for their potential in manipulating magnetic information.
Cavendish Laboratory, University of Cambridge, Cambridge CB3 0HE, UK.
Chiara
C
Ciccarelli
1] Department of Physics, Norwegian University of Science and Technology, NO-7491, Trondheim, Norway [2] Niels Bohr International Academy and the Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark.
Kjetil M D
KM
Hals
Cavendish Laboratory, University of Cambridge, Cambridge CB3 0HE, UK.
Andrew
A
Irvine
Institute of Physics ASCR, v.v.i., Cukrovarnická 10, 162 53 Praha 6, Czech Republic.
Vit
V
Novak
Department of Physics and Astronomy, University of California, Los Angeles, California 90095, USA.
Yaroslav
Y
Tserkovnyak
1] Cavendish Laboratory, University of Cambridge, Cambridge CB3 0HE, UK [2] PRESTO, Japan Science and Technology Agency, Kawaguchi 332-0012, Japan.
Hidekazu
H
Kurebayashi
Department of Physics, Norwegian University of Science and Technology, NO-7491, Trondheim, Norway.
Arne
A
Brataas
Cavendish Laboratory, University of Cambridge, Cambridge CB3 0HE, UK.
Andrew
A
Ferguson