Skip to main content

Research Repository

Advanced Search

All Outputs (55)

Resonance of terahertz phonons in an acoustic nanocavity (2018)
Journal Article
Sandeep, S., Heywood, S. L., Campion, R. P., Kent, A. J., & Kini, R. N. (2018). Resonance of terahertz phonons in an acoustic nanocavity. Physical Review B, 98(23), Article 235303. https://doi.org/10.1103/physrevb.98.235303

We show the resonant behavior of ∼0.5-THz longitudinal acoustic (LA) phonons in an acoustic nanocavity of thickness ∼28 nm sandwiched between two GaAs/AlAs superlattices (SLs). One of the SLs, upon excitation with an ultrafast optical pulse, acts as... Read More about Resonance of terahertz phonons in an acoustic nanocavity.

Electrically induced and detected Néel vector reversal in a collinear antiferromagnet (2018)
Journal Article
Godinho, J., Reichlová, H., Kriegner, D., Novák, V., Olejník, K., Kašpar, Z., …Wunderlich, J. (2018). Electrically induced and detected Néel vector reversal in a collinear antiferromagnet. Nature Communications, 9(1), Article 4686. https://doi.org/10.1038/s41467-018-07092-2

© 2018, The Author(s). Antiferromagnets are enriching spintronics research by many favorable properties that include insensitivity to magnetic fields, neuromorphic memory characteristics, and ultra-fast spin dynamics. Designing memory devices with el... Read More about Electrically induced and detected Néel vector reversal in a collinear antiferromagnet.

A high electron mobility phonotransistor (2018)
Journal Article
Poyser, C. L., Li, L. H., Campion, R. P., Akimov, A. V., Linfield, E. H., Davies, A. G., …Kent, A. J. (2018). A high electron mobility phonotransistor. Communications Physics, 1, 1-7. https://doi.org/10.1038/s42005-018-0059-7

Acoustoelectric devices convert acoustic energy to electrical energy and vice versa. Devices working at much higher acoustic frequencies than those currently available have potential scientific and technological applications, e.g.: as detectors in ph... Read More about A high electron mobility phonotransistor.

Current polarity-dependent manipulation of antiferromagnetic domains (2018)
Journal Article
Wadley, P., Reimers, S., Grzybowski, M. J., Andrews, C., Wang, M., Chauhan, J., …Jungwirth, T. (2018). Current polarity-dependent manipulation of antiferromagnetic domains. Nature Nanotechnology, 13(5), 362-365. https://doi.org/10.1038/s41565-018-0079-1

Antiferromagnets have several favourable properties as active elements in spintronic devices, including ultra-fast dynamics, zero stray fields and insensitivity to external magnetic fields. Tetragonal CuMnAs is a testbed system in which the antiferro... Read More about Current polarity-dependent manipulation of antiferromagnetic domains.

Terahertz electrical writing speed in an antiferromagnetic memory (2018)
Journal Article
Olejník, K., Seifert, T., Kašpar, Z., Novák, V., Wadley, P., Campion, R. P., …Jungwirth, T. (2018). Terahertz electrical writing speed in an antiferromagnetic memory. Science Advances, 4(3), Article eaar3566. https://doi.org/10.1126/sciadv.aar3566

© 2018 American Association for the Advancement of Science. All rights reserved. The speed of writing of state-of-the-art ferromagnetic memories is physically limited by an intrinsic gigahertz threshold. Recently, realization of memory devices based... Read More about Terahertz electrical writing speed in an antiferromagnetic memory.

Switching the uniaxial magnetic anisotropy by ion irradiation induced compensation (2018)
Journal Article
Yuan, Y., Amarouche, T., Xu, C., Rushforth, A., Böttger, R., Edmonds, K., …Zhou, S. (2018). Switching the uniaxial magnetic anisotropy by ion irradiation induced compensation. Journal of Physics D: Applied Physics, 51(14), https://doi.org/10.1088/1361-6463/aab1db

© 2018 IOP Publishing Ltd. In the present work, the uniaxial magnetic anisotropy of GaMnAsP is modified by helium ion irradiation. According to the micro-magnetic parameters, e.g. resonance fields and anisotropy constants deduced from ferromagnetic r... Read More about Switching the uniaxial magnetic anisotropy by ion irradiation induced compensation.

Phonon spectroscopy with chirped shear and compressive acoustic pulses (2017)
Journal Article
Poyser, C. L., York, W., Srikanthreddy, D., Glavin, B., Linnik, T., Campion, R., …Kent, A. (in press). Phonon spectroscopy with chirped shear and compressive acoustic pulses. Physical Review Letters, 119, Article 255502. https://doi.org/10.1103/PhysRevLett.119.255502

Picosecond duration compressive and shear phonon wave packets injected into (311) GaAs slabs transform after propagation through ?1??mm into chirped acoustic pulses with a frequency increasing in time due to phonon dispersion. By probing the temporal... Read More about Phonon spectroscopy with chirped shear and compressive acoustic pulses.

Control of antiferromagnetic spin axis orientation in bilayer Fe/CuMnAs films (2017)
Journal Article
Wadley, P., Edmonds, K., Shahedkhah, M., Campion, R., Gallagher, B., Železný, J., …Dhesi, S. (in press). Control of antiferromagnetic spin axis orientation in bilayer Fe/CuMnAs films. Scientific Reports, 7, Article 11147. https://doi.org/10.1038/s41598-017-11653-8

Using x-ray magnetic circular and linear dichroism techniques, we demonstrate a collinear exchange coupling between an epitaxial antiferromagnet, tetragonal CuMnAs, and an Fe surface layer. A small uncompensated Mn magnetic moment is observed which i... Read More about Control of antiferromagnetic spin axis orientation in bilayer Fe/CuMnAs films.

Antiferromagnetic CuMnAs multi-level memory cell with microelectronic compatibility (2017)
Journal Article
Olejnik, K., Schuler, V., Marti, X., Novák, V., Kaspar, Z., Wadley, P., …Jungwirth, T. (2017). Antiferromagnetic CuMnAs multi-level memory cell with microelectronic compatibility. Nature Communications, 8, Article 15434. https://doi.org/10.1038/ncomms15434

Antiferromagnets offer a unique combination of properties including the radiation and magnetic field hardness, the absence of stray magnetic fields, and the spin-dynamics frequency scale in terahertz. Recent experiments have demonstrated that relativ... Read More about Antiferromagnetic CuMnAs multi-level memory cell with microelectronic compatibility.

Inertial displacement of a domain wall excited byultra-short circularly polarized laser pulses (2017)
Journal Article
Janda, T., Roy, P., Otxoa, R., Soban, Z., Ramsay, A., Irvine, A., …Wunderlich, J. (2017). Inertial displacement of a domain wall excited byultra-short circularly polarized laser pulses. Nature Communications, 8, Article 15226. https://doi.org/10.1038/ncomms15226

Domain wall motion driven by ultra-short laser pulses is a prerequisite for envisaged low-power spintronics combining storage of information in magnetoelectronic devices with high speed and long distance transmission of information encoded in circula... Read More about Inertial displacement of a domain wall excited byultra-short circularly polarized laser pulses.

Investigation of exchange coupled bilayer Fe/CuMnAs by pump-probe experiment (2017)
Journal Article
Saidl, V., Němec, P., Wadley, P., Edmonds, K., Campion, R., Novák, V., …Trojánek, F. (in press). Investigation of exchange coupled bilayer Fe/CuMnAs by pump-probe experiment. physica status solidi (RRL) - Rapid Research Letters, 11(4), https://doi.org/10.1002/pssr.201600441

Time-resolved pump-probe magneto-optical method was used to study Fe/CuMnAs bilayer. The probe polarization dependence was used to identify and separate parts of detected signals due to Faraday and Voigt magneto-optical effects that provide informati... Read More about Investigation of exchange coupled bilayer Fe/CuMnAs by pump-probe experiment.

Effect of lithographically-induced strain relaxation on the magnetic domain configuration in microfabricated epitaxially grown Fe81Ga19 (2017)
Journal Article
Beardsley, R. P., Parkes, D. E., Zemen, J., Bowe, S., Edmonds, K. W., Reardon, C., …Rushforth, A. W. (2017). Effect of lithographically-induced strain relaxation on the magnetic domain configuration in microfabricated epitaxially grown Fe81Ga19. Scientific Reports, 7(1), Article 42107. https://doi.org/10.1038/srep42107

We investigate the role of lithographically-induced strain relaxation in a micron-scaled device fabricated from epitaxial thin films of the magnetostrictive alloy Fe81Ga19. The strain relaxation due to lithographic patterning induces a magnetic aniso... Read More about Effect of lithographically-induced strain relaxation on the magnetic domain configuration in microfabricated epitaxially grown Fe81Ga19.

Imaging current-induced switching of antiferromagnetic domains in CuMnAs (2017)
Journal Article
Grzybowski, M., Wadley, P., Edmonds, K., Beardsley, R., Hills, V. A., Campion, R., …Dhesi, S. (2017). Imaging current-induced switching of antiferromagnetic domains in CuMnAs. Physical Review Letters, 118(5), Article 057701. https://doi.org/10.1103/PhysRevLett.118.057701

The magnetic order in antiferromagnetic materials is hard to control with external magnetic fields. Using X-ray Magnetic Linear Dichroism microscopy, we show that staggered effective fields generated by electrical current can induce modification of t... Read More about Imaging current-induced switching of antiferromagnetic domains in CuMnAs.

Optical determination of the Néel vector in a CuMnAs thin-film antiferromagnet (2017)
Journal Article
Saidl, V., Němec, P., Wadley, P., Hills, V., Campion, R. P., Novák, V., …Jungwirth, T. (2017). Optical determination of the Néel vector in a CuMnAs thin-film antiferromagnet. Nature Photonics, 11(2), 91-96. https://doi.org/10.1038/nphoton.2016.255

Recent breakthroughs in electrical detection and manipulation of antiferromagnets have opened a new avenue in the research of non-volatile spintronic devices.1-10 Antiparallel spin sublattices in antiferromagnets, producing zero dipolar fields, lead... Read More about Optical determination of the Néel vector in a CuMnAs thin-film antiferromagnet.

Precise tuning of the Curie temperature of (Ga,Mn)As-based magnetic semiconductors by hole compensation: Support for valence-band ferromagnetism (2016)
Journal Article
Zhou, S., Li, L., Yuan, Y., Rushforth, A., Chen, L., Wang, Y., …Helm, M. (2016). Precise tuning of the Curie temperature of (Ga,Mn)As-based magnetic semiconductors by hole compensation: Support for valence-band ferromagnetism. Physical Review B, 94(7), https://doi.org/10.1103/PhysRevB.94.075205

For the prototype diluted ferromagnetic semiconductor (Ga,Mn)As, there is a fundamental concern about the electronic states near the Fermi level, i.e., whether the Fermi level resides in a well-separated impurity band derived from Mn doping (impurity... Read More about Precise tuning of the Curie temperature of (Ga,Mn)As-based magnetic semiconductors by hole compensation: Support for valence-band ferromagnetism.

The UK National Quantum Technologies Hub in sensors and metrology (Keynote Paper) (2016)
Journal Article
Bongs, K., Boyer, V., Cruise, M., Freise, A., Holynski, M., Hughes, J., …John, P. (2016). The UK National Quantum Technologies Hub in sensors and metrology (Keynote Paper). Proceedings of SPIE, 9900, Article 990009. https://doi.org/10.1117/12.2232143

The UK National Quantum Technology Hub in Sensors and Metrology is one of four flagship initiatives in the UK National of Quantum Technology Program. As part of a 20-year vision it translates laboratory demonstrations to deployable practical devices,... Read More about The UK National Quantum Technologies Hub in sensors and metrology (Keynote Paper).

Three-dimensional Heisenberg critical behavior in the highly disordered dilute ferromagnetic semiconductor (Ga,Mn)As (2016)
Journal Article
Wang, M., Marshall, R. A., Edmonds, K. W., Rushforth, A., Campion, R., & Gallagher, B. (2016). Three-dimensional Heisenberg critical behavior in the highly disordered dilute ferromagnetic semiconductor (Ga,Mn)As. Physical Review B, 93(18), Article 184417. https://doi.org/10.1103/PhysRevB.93.184417

We present detailed studies of critical behavior in the strongly site-disordered dilute ferromagnetic semiconductor (Ga,Mn)As. (Ga,Mn)As has a low saturation magnetization and relatively strong magnetocrystalline anisotropy. This combination of prop... Read More about Three-dimensional Heisenberg critical behavior in the highly disordered dilute ferromagnetic semiconductor (Ga,Mn)As.

Intrinsic magnetic refrigeration of a single electron transistor (2016)
Journal Article
Ciccarelli, C., Campion, R., Gallagher, B., & Ferguson, A. (2016). Intrinsic magnetic refrigeration of a single electron transistor. Applied Physics Letters, 108(5), Article 053103. https://doi.org/10.1063/1.4941289

In this work, we show that aluminium doped with low concentrations of magnetic impurities can be used to fabricate quantum devices with intrinsic cooling capabilities. We fabricate single electron transistors made of aluminium doped with 2% Mn by usi... Read More about Intrinsic magnetic refrigeration of a single electron transistor.

Electrical switching of an antiferromagnet (2016)
Journal Article
Wadley, P., Howells, B., Železný, J., Andrews, C., Hills, V., Campion, R. P., …Jungwirth, T. (2016). Electrical switching of an antiferromagnet. Science, 351(6273), 587-590. https://doi.org/10.1126/science.aab1031

Antiferromagnets are hard to control by external magnetic fields because of the alternating directions of magnetic moments on individual atoms and the resulting zero net magnetization. However, relativistic quantum mechanics allows for generating cur... Read More about Electrical switching of an antiferromagnet.

Antiferromagnetic structure in tetragonal CuMnAs thin films (2015)
Journal Article
Wadley, P., Hills, V. A., Shahedkhah, M. R., Edmonds, K. W., Campion, R. P., Novák, V., …Jungwirth, T. (2015). Antiferromagnetic structure in tetragonal CuMnAs thin films. Scientific Reports, 5(1), Article 17079. https://doi.org/10.1038/srep17079

Tetragonal CuMnAs is an antiferromagnetic material with favourable properties for applications in spintronics. Using a combination of neutron diffraction and x-ray magnetic linear dichroism, we determine the spin axis and magnetic structure in tetrag... Read More about Antiferromagnetic structure in tetragonal CuMnAs thin films.