TY - JOUR

T1 - Coherent spin-wave transport in an antiferromagnet

AU - Hortensius, J.R.

AU - Afanasiev, D.

AU - Matthiesen, M.

AU - Leenders, R.

AU - Citro, R.

AU - Kimel, A.V.

AU - Mikhaylovskiy, R.V.

AU - Ivanov, B.A.

AU - Caviglia, A.D.

PY - 2021/7/29

Y1 - 2021/7/29

N2 - Magnonics is a research field complementary to spintronics, in which the quanta of spin waves (magnons) replace electrons as information carriers, promising lower dissipation1–3. The development of ultrafast, nanoscale magnonic logic circuits calls for new tools and materials to generate coherent spin waves with frequencies as high and wavelengths as short as possible4,5. Antiferromagnets can host spin waves at terahertz frequencies and are therefore seen as a future platform for the fastest and least dissipative transfer of information6–11. However, the generation of short-wavelength coherent propagating magnons in antiferromagnets has so far remained elusive. Here we report the efficient emission and detection of a nanometre-scale wavepacket of coherent propagating magnons in the antiferromagnetic oxide dysprosium orthoferrite using ultrashort pulses of light. The subwavelength confinement of the laser field due to large absorption creates a strongly non-uniform spin excitation profile, enabling the propagation of a broadband continuum of coherent terahertz spin waves. The wavepacket contains magnons with a shortest detected wavelength of 125 nm that propagate into the material with supersonic velocities of more than 13 km s–1. This source of coherent short-wavelength spin carriers opens up new prospects for terahertz antiferromagnetic magnonics and coherence-mediated logic devices at terahertz frequencies.

AB - Magnonics is a research field complementary to spintronics, in which the quanta of spin waves (magnons) replace electrons as information carriers, promising lower dissipation1–3. The development of ultrafast, nanoscale magnonic logic circuits calls for new tools and materials to generate coherent spin waves with frequencies as high and wavelengths as short as possible4,5. Antiferromagnets can host spin waves at terahertz frequencies and are therefore seen as a future platform for the fastest and least dissipative transfer of information6–11. However, the generation of short-wavelength coherent propagating magnons in antiferromagnets has so far remained elusive. Here we report the efficient emission and detection of a nanometre-scale wavepacket of coherent propagating magnons in the antiferromagnetic oxide dysprosium orthoferrite using ultrashort pulses of light. The subwavelength confinement of the laser field due to large absorption creates a strongly non-uniform spin excitation profile, enabling the propagation of a broadband continuum of coherent terahertz spin waves. The wavepacket contains magnons with a shortest detected wavelength of 125 nm that propagate into the material with supersonic velocities of more than 13 km s–1. This source of coherent short-wavelength spin carriers opens up new prospects for terahertz antiferromagnetic magnonics and coherence-mediated logic devices at terahertz frequencies.

KW - Antiferromagnetic materials

KW - Antiferromagnetism

KW - Computer circuits

KW - Laser excitation

KW - Logic devices

KW - Nanostructured materials

KW - Spin waves

KW - Supersonic aircraft

KW - Wave packets

KW - Antiferromagnetics

KW - Antiferromagnets

KW - Efficient emission

KW - Information carriers

KW - Short wavelengths

KW - Supersonic velocities

KW - Terahertz frequencies

KW - Transfer of information

KW - Terahertz waves

U2 - 10.1038/s41567-021-01290-4

DO - 10.1038/s41567-021-01290-4

M3 - Journal article

VL - 17

JO - Nature Physics

JF - Nature Physics

SN - 1745-2473

ER -