Professional Course
Since 2021 | Group Leader: Solid State Structures, Laboratory for Neutron Scattering and Imaging, Paul Scherrer Institut, CH | link |
Since 2016 | Senior Scientist, Laboratory for Neutron Scattering and Imaging, Paul Scherrer Institut, CH | |
2013-2016 | Tenure-Track Scientist, Laboratory for Neutron Scattering and Imaging, Paul Scherrer Institut, CH | |
2011-2013 | Postdoctoral Research Fellow, Laboratory for Quantum Magnetism, EPFL, CH | link |
2009-2013 | Postdoctoral Research Fellow, Laboratory for Neutron Scattering, Paul Scherrer Institut, CH | |
2006-2009 | Ph.D. studies, Condensed Matter Physics Group, Department of Physics and Astronomy, University of Birmingham, UK Ph.D. Thesis: SANS Investigations of the Flux Line Lattice in Unconventional Superconductors |
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2006 | Summer Stagiaire Programme, Institut Laue-Langevin, Grenoble, FR | link |
2002-2006 | MSci in Physics at the University of Birmingham, UK Masters Thesis: Hybrid Device Structures Based on Normal Metal - High Temperature Superconductor Contacts |
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Interests and Responsibilities
My principal scientific interests are in experimental Condensed Matter Physics, where I use mainly neutron scattering to attack various problems. Topics of current interest include:
- Search for novel magnetic phases in topological materials
- Topological magnetism, mainly in non-centrosymmetric lattices
- Microscopic mechanisms for magnetoelectric coupling, in both thin film and bulk materials
- Interaction between superconductivity and other orders
- Realization of challenging experiments, e.g. complex sample environments, small sample volumes, pressure experiments.
- Responsible for the SANS-I instrument at SINQ.
- At this link you can find a Youtube video where I provide an introduction to SANS-I and its application to SANS diffraction studies of hard condensed matter systems - my specialist expertise!
Projects and Collaborative Activities
- Title: Discovery of new quantum effects derived from synergies between magnetism and Weyl electrons, Role: PI with N. Kanazawa (Univ. of Tokyo), Sponsor: ETHZ (Research Partnership Grant), Funds: 25 kCHF, Jun 2022- May 2023
- Title: Creation and exploration of high-density topological skyrmion phases in 4f magnets, Role: PI, Sponsor: SNSF (Project), Funds: 0.46 MCHF, Nov 2020 to Oct 2024
- Title: Discovery and Nanoengineering of Novel Skyrmion-hosting materials, Role: co-PI (with Prof. D. Grundler (EPFL, PI), Prof. O. Yazyev (EPFL, co-PI) and Prof. M. Poggio (UBasel, co-PI)), Sponsor: SNSF (Sinergia), Funds: 2.7 MCHF (personal share 0.7 MCHF), Oct 2017 to Sep 2022 - Project website hosted by EPFL
- Title: Exploration of emerging magnetoelectric coupling effects in new materials, Role: PI, Sponsor: SNSF (Project), Funds: 0.2 MCHF, Jul 2015 to Jun 2018
Selected publications
Full list at Publons or Google Scholar
Transition between distinct hybrid skyrmion textures through their hexagonal-to-square crystal transformation in a polar magnet
D. Singh, Y. Fujishiro, S. Hayami, S.H. Moody, T. Nomoto, P.R. Baral, V. Ukleev, R. Cubitt, N.-J. Steinke, D.J. Gawryluk, E. Pomjakushina, Y. Onuki, R. Arita, Y. Tokura, N. Kanazawa, and J.S. White.
Nature Communications 14, 8050 (2023)
Neutron Techniques: Flux-Line Lattice
J. White.
Chapter G1.6 in "Handbook of Superconductivity: Characterization and Applications", 2nd Edition, Eds. D.A. Cardwell, D.C. Larbalestier, A. Braginski, CRC Press - Boca Raton, (2022)
Square and rhombic lattices of magnetic skyrmions in a centrosymmetric binary compound
R. Takagi, N. Matsuyama, V. Ukleev, L. Yu, J.S. White, S. Francoual, J.R.L. Mardegan, S. Hayami, H. Saito, K. Kaneko, K. Ohishi, Y. Onuki, T. Arima, Y. Tokura, T. Nakajima, and S. Seki.
Nature Communications 13, 1472 (2022)
Frustration-driven magnetic fluctuations as the origin of the low-temperature skyrmion phase in Co7Zn7Mn6
V. Ukleev, K. Karube, P.M. Derlet, C.N. Wang, H. Luetkens, D. Morikawa, A. Kikkawa, L. Mangin-Thro, A.R. Wildes, Y. Yamasaki, Y. Yokoyama, L. Yu, C. Piamonteze, N. Jaouen, Y. Tokunaga, H. M. Rønnow, T. Arima, Y. Tokura, Y. Taguchi, and J.S. White
npj Quantum Materials 6, 40 (2021)
Direct Observation of the Statics and Dynamics of Emergent Magnetic Monopoles in a Chiral Magnet
N. Kanazawa†, A. Kitaori†, J. S. White†, V. Ukleev, H. M. Rønnow, A. Tsukazaki, M. Ichikawa, M. Kawasaki, and Y. Tokura
Phys. Rev. Lett. 125, 137202 (2020)
Magnetism and anomalous transport in the Weyl semimetal PrAlGe: possible route to axial gauge fields
D. Destraz, L. Das, S.S. Tsirkin, Y. Xu, T. Neupert, J. Chang, A. Schilling, A.G. Grushin, J. Kohlbrecher, L. Keller, P. Puphal, E. Pomjakushina, and J.S. White
npj Quantum Materials 5, 5 (2020)
Topological magnetic phase in the candidate Weyl semimetal CeAlGe
P. Puphal, V. Pomjakushin, N. Kanazawa, V. Ukleev, D.J. Gawryluk, J.-Z. Ma, M. Naamneh, N.C. Plumb, L. Keller, R. Cubitt, E. Pomjakushina and, J.S. White
Phys. Rev. Lett. 124, 017202 (2020)
Multiple-q noncollinear magnetism in an itinerant hexagonal magnet
R. Takagi, J.S. White, S. Hayami, R. Arita, D. Honecker, H.M. Rønnow, Y. Tokura, and S. Seki
Science Advances, 4, eaau3402 (2018).
Disordered skyrmion phase stabilized by magnetic frustration in a chiral magnet
K. Karube†, J.S. White†, D. Morikawa, C.D. Dewhurst, R. Cubitt, A. Kikkawa, X.Z. Yu, Y. Tokunaga, T. Arima, H.M. Rønnow, Y. Tokura, and Y. Taguchi
Science Advances, 4, eaar7043 (2018).
Magnetoelectric inversion of domain patterns
N. Leo†, V. Carolus†, J.S. White, M. Kenzelmann, M. Hudl, P. Toledano, T. Honda, T. Kimura, S.A. Ivanov, M. Weil, Th. Lottermoser, D. Meier, and M. Fiebig
Nature 560, 466 (2018).
Coupled multiferroic domain switching in the canted conical spin spiral system Mn2GeO4
T. Honda†, J.S. White†, A.B. Harris, L.C. Chapon, A. Fennell, B. Roessli, O. Zaharko, M. Kenzelmann, and T. Kimura
Nature Communications 8, 15457 (2017).
Robust metastable skyrmions and their triangular–square lattice structural transition in a high-temperature chiral magnet
K. Karube†, J.S. White†, N. Reynolds, J.L. Gavilano, H. Oike, A. Kikkawa, F. Kagawa, Y. Tokunaga, H.M. Rønnow, Y. Tokura, and Y. Taguchi
Nature Materials 15, 1237 (2016).
Néel-type Skyrmion Lattice with Confined Orientation in the Polar Magnetic Semiconductor GaV4S8
I. Kézsmárki, S. Bordács, P. Milde, E. Neuber, L.M. Eng, J.S. White, H.M. Rønnow, C.D. Dewhurst, M. Mochizuki, K. Yanai, H. Nakamura, D. Ehlers, V. Tsurkan, and A. Loidl
Nature Materials 14, 1116 (2015).
A new class of chiral materials hosting magnetic skyrmions beyond room temperature
Y. Tokunaga, X.Z. Yu, J.S. White, H.M. Rønnow, D. Morikawa, Y. Taguchi, and Y. Tokura
Nature Communications 6, 7638 (2015).
Electric field-induced Skyrmion distortion and giant lattice rotation in the magnetoelectric insulator Cu2OSeO3
J.S. White, K. Prša, P. Huang, A.A. Omrani, I. Živković, M. Bartkowiak, H. Berger, A. Magrez, J.L. Gavilano, G. Nagy, J. Zang, and H.M. Rønnow
Phys. Rev. Lett. 113, 107203 (2014).
Strain-Induced Ferromagnetism in Antiferromagnetic LuMnO3 Thin Films
J.S. White, M. Bator, Y. Hu, H. Luetkens, J. Stahn, S. Capelli, S. Das, M. Döbeli, Th. Lippert, V.K. Malik, J. Martynczuk, A. Wokaun, M. Kenzelmann, Ch. Niedermayer, and C.W. Schneider
Phys. Rev. Lett. 111, 037201 (2013).
Coupling of Magnetic and Ferroelectric Hysteresis by a Multicomponent Magnetic Structure in Mn2GeO4
J.S. White, T. Honda, K. Kimura, T. Kimura, Ch. Niedermayer, O. Zaharko, A. Poole, B. Roessli, and M. Kenzelmann
Phys. Rev. Lett. 108, 077204 (2012).
Fermi Surface and Order Parameter Driven Vortex Lattice Structure Transitions in Twin-Free YBa2Cu3O7
J.S. White, V. Hinkov, R.W. Heslop, R.J. Lycett, E.M. Forgan, C. Bowell, S. Strässle, A.B. Abrahamsen, M. Laver, C.D. Dewhurst, J. Kohlbrecher, J.L. Gavilano, J. Mesot, B. Keimer, and A. Erb
Phys. Rev. Lett. 102, 097001 (2009).
Superconducting Vortices in CeCoIn5: Toward the Pauli-Limiting Field
A.D. Bianchi, M. Kenzelmann, L. DeBeer-Schmitt, J.S. White, E.M. Forgan, J. Mesot, M. Zolliker, J. Kohlbrecher, R. Movshovich, E.D. Bauer, J.L. Sarrao, Z. Fisk, C. Petrović, and M.R. Eskildsen
Science 319, 177 (2008).
Recent Presentations
Observation of hybrid skyrmions and their lattice transitions in a bulk magnet | Contributed Talk, UK-Swiss Workshop on Skyrmions, EPFL, CH | 21.08.2023 |
Control of the emergent inductance in helimagnet YMn6Sn6 via Tb substitution | Contributed Talk, ECNS 2023, Garching, DE | 23.03.2023 |
Frustration-driven magnetic fluctuations as the origin of the low-temperature skyrmion phase in Co7Zn7Mn6 | Invited talk at 84th DPG Meeting, DE (delivered online) | 28.09.2021 |
Multi-k magnetic phases and topological charges in the candidate Weyl semimetal CeAlGe | Invited Talk, IUCr 2021, Prague, CZ (delivered online) | 16.08.2021 |
Exploring Magnetic Skyrmions in Co-Zn-Mn Compounds: From Far-From-Equilibrium States to Effects of Magnetic Frustration | Invited Talk, 2021 MRS Spring Meeting, Seattle, US (delivered online) | 21.04.2021 |
Topological magnetic phase in the candidate Weyl semimetal CeAlGe | Invited Talk, 6th RIKEN CEMS Topical Meeting, Wako, JP (delivered online) | 01.12.2020 |
Magnetic skyrmions at room temperature and far-from-equilibrium | Condensed Matter Seminar (Invited), University of Notre Dame, US (delivered online) | 27.08.2020 |
Magnetic skyrmions at room temperature and far-from-equilibrium | PSI Condensed Matter Colloquium (Invited), Paul Scherrer Institut, CH | 24.01.2020 |
Colleagues
In addition to other LNS members, I also work with the below-listed scientists and their group members. Please take a moment to visit their webpages.
Dr. M. Bartkowiak, LIN, PSI | link |
Prof. S. Bordács, BUTE, Hungary | link |
Dr. R. Cubitt, Dr. C.D. Dewhurst, Dr. N.-J. Steinke, Institut Laue-Langevin, France | link |
Prof. M.R. Eskildsen, University of Notre Dame, USA | link |
Prof. E.M. Forgan, University of Birmingham, UK | link |
Prof. N. Kanazawa, Institute of Industrial Science, University of Tokyo, Japan | link |
Prof. T. Kimura, Department of Applied Physics, University of Tokyo, Japan | link |
Dr. D. Gawryluk, Dr. E. Pomjakushina, LMX, PSI | link |
Prof. H.M. Rønnow, Dr. I. Živković, Dr. A. Magrez, EPFL | link |
Prof. Y. Tokura, Department of Applied Physics, University of Tokyo, Japan | link |
Prof. Y. Tokura, Prof. Y. Taguchi, Dr. K. Karube, RIKEN CEMS, Wako, Japan | link |
Dr. V. Ukleev, Helmholtz-Zentrum Berlin, Germany | link |
Prof. Y. Yasui, Meiji University, Japan | link |