Skip to main content

Research Repository

Advanced Search

All Outputs (58)

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., Novák, V., Olejnik, K., Maccherozzi, F., Dhesi, S. S., Martin, S. Y., Wagner, T., Wunderlich, J., Freimuth, F., Mokrousov, Y., Kunes, J., Chauhan, J., Grzybowski, M. J., Rushforth, A. W., Edmonds, K. W., …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., Ouladdiaf, B., Khalyavin, D., Langridge, S., Saidl, V., Němec, P., Rushforth, A. W., Gallagher, B. L., Dhesi, S. S., Maccherozzi, F., Železný, J., & 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.

Magnetic coupling in ferromagnetic semiconductor (Ga,Mn)As/(Al,Ga,Mn)As bilayers (2015)
Journal Article
Wang, M., Wadley, P., Campion, R. P., Rushforth, A. W., Edmonds, K. W., Gallagher, B. L., Charlton, T. R., Kinane, C. J., & Langridge, S. (2015). Magnetic coupling in ferromagnetic semiconductor (Ga,Mn)As/(Al,Ga,Mn)As bilayers. Journal of Applied Physics, 118(5), Article 053913. https://doi.org/10.1063/1.4928206

We report on a study of ferromagnetic semiconductor (Ga,Mn)As/(Al,Ga,Mn)As bilayers using magnetometry and polarized neutron reflectivity (PNR). From depth-resolved characterization of the magnetic structure obtained by PNR, we concluded that the (Ga... Read More about Magnetic coupling in ferromagnetic semiconductor (Ga,Mn)As/(Al,Ga,Mn)As bilayers.

Resonant driving of magnetization precession in a ferromagnetic layer by coherent monochromatic phonons (2015)
Journal Article
Jäger, J., Scherbakov, A., Glavin, B., Salasyuk, A., Campion, R., Rushforth, A., Yakovlev, D., Akimov, A. V., & Bayer, M. (2015). Resonant driving of magnetization precession in a ferromagnetic layer by coherent monochromatic phonons. Physical review B: Condensed matter and materials physics, 92(2), https://doi.org/10.1103/PhysRevB.92.020404

We realize resonant driving of the magnetization precession by monochromatic phonons in a thin ferromagnetic layer embedded into a phononic Fabry-Pérot resonator. A femtosecond laser pulse excites resonant phonon modes of the structure in the 10−40 G... Read More about Resonant driving of magnetization precession in a ferromagnetic layer by coherent monochromatic phonons.

Coherent phonon optics in a chip with an electrically controlled active device (2015)
Journal Article
Akimov, A., Poyser, C. L., Kent, A. J., & CAMPION, R. (2015). Coherent phonon optics in a chip with an electrically controlled active device. Scientific Reports, 5, Article 8279. https://doi.org/10.1038/srep08279

Phonon optics concerns operations with high-frequency acoustic waves in solid media in a similar way to how traditional optics operates with the light beams (i.e. photons). Phonon optics experiments with coherent terahertz and sub-terahertz phonons p... Read More about Coherent phonon optics in a chip with an electrically controlled active device.

Comparison of micromagnetic parameters of the ferromagnetic semiconductors (Ga,Mn)(As,P) and (Ga,Mn)As (2014)
Journal Article
Tesařová, N., Butkovičová, D., Campion, R. P., Rushforth, A. W., Edmonds, K. W., Wadley, P., Gallagher, B. L., Schmoranzerová, E., Trojánek, F., Malý, P., Motloch, P., Novák, V., Jungwirth, T., & Němec, P. (2014). Comparison of micromagnetic parameters of the ferromagnetic semiconductors (Ga,Mn)(As,P) and (Ga,Mn)As. Physical review B: Condensed matter and materials physics, 90(15), Article 155203. https://doi.org/10.1103/physrevb.90.155203

We report on the determination of micromagnetic parameters of epilayers of the ferromagnetic semiconductor (Ga,Mn)As, which has an easy axis in the sample plane, and (Ga,Mn)(As,P), which has an easy axis perpendicular to the sample plane.We use an op... Read More about Comparison of micromagnetic parameters of the ferromagnetic semiconductors (Ga,Mn)(As,P) and (Ga,Mn)As.

Determining Curie temperatures in dilute ferromagnetic semiconductors: high Curie temperature (Ga,Mn)As (2014)
Journal Article
Wang, M., Marshall, R., Edmonds, K., Rushforth, A., Campion, R., & Gallagher, B. (2014). Determining Curie temperatures in dilute ferromagnetic semiconductors: high Curie temperature (Ga,Mn)As. Applied Physics Letters, 104, Article 132406. https://doi.org/10.1063/1.4870521

In this paper, we use simultaneous magnetometry and electrical transport measurements to critically examine ways in which the Curie temperature (TC) values have been determined in studies of dilute magnetic semiconductors. We show that, in sufficient... Read More about Determining Curie temperatures in dilute ferromagnetic semiconductors: high Curie temperature (Ga,Mn)As.

III-V semiconductor waveguides for photonic functionality at 780 nm (2014)
Presentation / Conference Contribution
Maclean, J. O., Greenaway, M. T., Campion, R. P., Pyragius, T., Fromhold, T. M., Kent, A. J., & Mellor, C. J. III-V semiconductor waveguides for photonic functionality at 780 nm. Presented at SPIE OPTO, San Francisco, California, United States

Photonic integrated circuits based on III-V semiconductor polarization-maintaining waveguides were designed and fabricated for the first time for application in a compact cold-atom gravimeter1,2 at an operational wavelength of 780 nm. Compared with o... Read More about III-V semiconductor waveguides for photonic functionality at 780 nm.

An antidamping spin–orbit torque originating from the Berry curvature (2014)
Journal Article
Kurebayashi, H., Sinova, J., Fang, D., Irvine, A. C., Skinner, T. D., Wunderlich, J., Novák, V., Campion, R. P., Gallagher, B. L., Vehstedt, E. K., Zârbo, L. P., Výborný, K., Ferguson, A. J., & Jungwirth, T. (2014). An antidamping spin–orbit torque originating from the Berry curvature. Nature Nanotechnology, 9(3), 211-217. https://doi.org/10.1038/nnano.2014.15

Magnetization switching at the interface between ferromagnetic and paramagnetic metals, controlled by current-induced torques, could be exploited in magnetic memory technologies. Compelling questions arise regarding the role played in the switching b... Read More about An antidamping spin–orbit torque originating from the Berry curvature.

Dynamics of a vertical cavity quantum cascade phonon laser structure (2013)
Journal Article
Maryam, W., Akimov, A. V., Campion, R., & Kent, A. (2013). Dynamics of a vertical cavity quantum cascade phonon laser structure. Nature Communications, 4, Article 2184. https://doi.org/10.1038/ncomms3184

Driven primarily by scientific curiosity, but also by the potential applications of intense sources of coherent sound, researchers have targeted the phonon laser (saser) since the invention of the optical laser over 50 years ago. Here we fabricate a... Read More about Dynamics of a vertical cavity quantum cascade phonon laser structure.

Magnetostrictive thin films for microwave spintronics (2013)
Journal Article
Parkes, D., Shelford, L., Wadley, P., Holy, V., Wang, M., Hindmarch, A., van der Laan, G., Edmonds, K., Campion, R., Cavill, S., & Rushforth, A. (2013). Magnetostrictive thin films for microwave spintronics. Scientific Reports, 3, Article 2220. https://doi.org/10.1038/srep02220

Multiferroic composite materials, consisting of coupled ferromagnetic and piezoelectric phases, are of great importance in the drive towards creating faster, smaller and more energy efficient devices for information and communications technologies. S... Read More about Magnetostrictive thin films for microwave spintronics.

Nanoscale characterisation of MBE-grown GaMnN / (001) GaAs (2008)
Book Chapter
Fay, M. W., Han, Y., Novikov, S. V., Edmonds, K., Gallagher, B., Campion, R., Staddon, C., Foxon, C., & Brown, P. D. (2008). Nanoscale characterisation of MBE-grown GaMnN / (001) GaAs. In A. Cullis, & P. Midgley (Eds.), Microscopy of semiconducting materials 2007: proceedings of the 15th conference, 2-5 April 2007, Cambridge, UK. Springer-Verlag

The growth of cubic (Ga,Mn)N/(001)GaAs heterostructures by plasma assisted molecular beam epitaxy has been appraised as a function of Ga:N ratio, Mn concentration and growth temperature. The combined analytical techniques of EFTEM, EDX, CBED and dark... Read More about Nanoscale characterisation of MBE-grown GaMnN / (001) GaAs.

Structural characterisation of spintronic GaMnAs and GaMnN heterostructures grown by molecular beam epitaxy (2005)
Book Chapter
Fay, M. W., Han, Y., Novikov, S. V., Edmonds, K., Wang, K., Gallagher, B., Campion, R., Foxon, C., & Brown, P. D. (2005). Structural characterisation of spintronic GaMnAs and GaMnN heterostructures grown by molecular beam epitaxy. In A. Cullis, & A. Hutchison (Eds.), Microscopy of semiconducting materials: proceedings of the 14th conference: April 11-14, 2005, Oxford, UK. Springer-Verlag

Observations of orthogonal orientations demonstrate the development of banded contrast features on inclined {-1-1-1}B planes for the [110] projection within micron thick samples, attributed to a compositional fluctuation in the Mn content. The relat... Read More about Structural characterisation of spintronic GaMnAs and GaMnN heterostructures grown by molecular beam epitaxy.

Structural characterisation of MBE grown zinc-blende Ga1-xMnxN/GaAs(001) as a function of Ga flux (2005)
Book Chapter
Han, Y., Fay, M. W., Brown, P. D., Novikov, S. V., Edmonds, K., Gallagher, B., Campion, R., & Foxon, C. (2005). Structural characterisation of MBE grown zinc-blende Ga1-xMnxN/GaAs(001) as a function of Ga flux. In A. Cullis, & J. Hutchison (Eds.), Microscopy of semiconducting materials: proceedings of the 14th conference: April 11-14, 2005, Oxford, UK. Springer-Verlag

Ga1-xMnxN films grown on semi-insulating GaAs(001) substrates at 680°C with fixed Mn flux and varied Ga flux demonstrated a transition from zinc-blende/wurtzite mixed phase growth for low Ga flux (N-rich conditions) to zinc-blende single phase growth... Read More about Structural characterisation of MBE grown zinc-blende Ga1-xMnxN/GaAs(001) as a function of Ga flux.