Quantum conductors and magnets
Introduction
Quantum conductors and magnets offer the possibility to investigate a large range of new quantum phenomena. Amongst them, quantum phase transitions delimiting different magnetic phases, unconventional superconductivity, valence transitions and crossovers. A challenge is to discover new quantum phases and elucidate their microscopic nature.
The team ‘Quantum Conductors and Magnets’ (‘Conducteurs et Aimants Quantiques’) is based at the LNCMI-Toulouse. It combines microscopic (neutrons, x-rays) and bulk (resistivity, magnetization) probes for the experimental investigation of quantum materials under intense magnetic fields (up to 90 T and 100 T soon), high pressures (up to 6 GPa) and low temperatures (down to 100 mK).
Amongst our recent works, we can cite the discovery of field induced superconductivity in UTe2, the study of the magnetic structure of TbB4, but also the development of state-of-the-art instrumentation, as a 40 T magnet for neutron diffraction, a pressure cell for electrical resistivity in pulsed fields up to 60 T and pressures up to 6 GPa.
CONTACT
For neutron and x-ray experiments under pulsed fields: Fabienne Duc
For electrical resistivity under pulsed fields: William Knafo
About the team
Permanent Researchers
SCIENTIFIC FIELDS
- Quantum magnetism
- Correlated-electrons physics
- Heavy-fermion systems
- Unconventional superconductivity
- Quantum phase transitions
- Low-dimensional magnetism
- Frustrated magnetism
MEMBERS OF THE TEAM
- Fabienne Duc, Chargée de Recherche
- William Knafo, Chargé de Recherche
- Somesh Kalaiarasan, Post-doc
FORMER MEMBERS OF THE TEAM
- Tristan Thebault, PhD
- Emin Mijit, Post-doc
- Alain Audouard, Chargé de Recherche
- Naveen Kumar, Post-doc
- Xavier Fabrèges, Post-doc
- Armelle Poux PhD
- Gernot Scheerer, PhD
MAIN COLLABORATIONS
- ESRF-Grenoble
- ILL-Grenoble
- CEA-Grenoble
- University of Tohoku
Experimental techniques
In recent years, the team has developed a unique panel of microscopic and macroscopic probes to study the electronic properties of correlated electron systems under extreme conditions of intense magnetic field, which can be combined with low temperature and high pressure.
- At the LNCMI-T site, a various set of extreme conditions can be combined for electrical resistivity and magnetization measurements: magnetic fields up to 90 T (and >100 T soon), high pressures up to 6 GPa or temperatures down to 100 mK combined with magnetic fields up to 60 T.
- At the ESRF synchrotron facility, X-ray (absorption and magnetic circular dichroism) spectroscopy in pulsed field allows accessing the valence and element-selective magnetization of materials under magnetic fields up to 30 T.
- At the ILL neutron source, neutron diffraction permits determining the magnetic structure of magnets in magnetic fields up to 40 T.
Neutron diffraction
- pulsed fields up to 40 T + temperatures from 2 to 300 K
- experiments on IN22 (CEA-CRG) at the ILL Grenoble
X-rays
- pulsed fields up to 30 T + temperatures from 2 to 300 K
- XAS and XMCD experiments on ID24 at the ESRF Grenoble
Electrical resistivity
Different environments combining extreme conditions are available for electrical-resistivity measurements:
- pulsed fields up to 96 T + temperatures from 1.5 to 300 K (4He cryostat)
- pulsed fields up to 70 T + temperatures from 1.5 to 300 K (4He cryostat)
- pulsed fields up to 60 T + pressure up to 6 GPa + temperatures from 1.5 to 300 K (4He cryostat)
- pulsed fields up to 60 T + temperatures from 500 mK to 300 K (3He cryostat)
- pulsed fields up to 60 T + temperatures from 100 mK to 300 K (dilution): available in 2026
Publications
Selected Publications
- “Comparison of two superconducting phases induced by a magnetic field in UTe2“, W. Knafo, M. Nardone, M. Valiska, A. Zitouni, G. Lapertot, D. Aoki, G. Knebel, D. Braithwaite, Commun. Phys. 4, 40 (2021).
- “Destabilization of hidden order in URu2Si2 under magnetic field and pressure“, W. Knafo, S. Araki, G. Lapertot, D. Aoki, G. Knebel, and D. Braithwaite, Nature Phys. 16, 942–948 (2020).
- “Field-reentrant superconductivity close to a metamagnetic transition in the heavy-fermion superconductor UTe2“, G. Knebel, W. Knafo, A. Pourret, Q. Niu, M. Valiska, D. Braithwaite, G. Lapertot, M. Nardone, A. Zitouni, S. Mishra, I. Sheikin, G. Seyfarth, J.-P. Brison, D. Aoki, J. Flouquet, J. Phys. Soc. Jpn. 88, 063707 (2019).
- “Pressure cell for transport measurements under high pressure and low temperature in pulsed magnetic fields“, D. Braithwaite, W. Knafo, R. Settai, D. Aoki, S. Kurahashi, and J. Flouquet, Rev. Sci. Instrum. 87, 023907 (2016).
- “Dichotomy between the hole and electrons behavior in the multiband FeSe probed by ultra high magnetic fields”, M.D. Watson, T. Yamashita, S. Kasahara, W. Knafo, M. Nardone, J. Béard, F. Hardy, A. McCollam, A. Narayanan, S.F. Blake, T. Wolf, A.A. Haghighirad, C. Meingast, A.J. Schofield, H. von Löhneysen, Y. Matsuda, A.I. Coldea, and T. Shibauchi, Phys. Rev. Lett. 115, 027006 (2015).
Neutron diffraction:
- Field-driven spin-structure evolution in MnCr2S4: A high-field single-crystal neutron-diffraction study, F. Duc, N. Qureshi, H. Suwa, E. Ressouche, M. Songvilay, O. Prokhnenko, A. Gazizulina, F. Bourdarot, V. Tsurkan, S. Zherlitsyn, L. Prodan, A. Bertin, A. Schneidewind, A. Hoser, M. Uhlarz, T; Herrmannsdörfer, J. Wosnitza, V. Simonet and S. Chattopadhyay, Phys. Rev. B 110, 214416 (2024).
- Possible stripe phases in the multiple magnetization plateaus in TbB4 from single-crystal neutron diffraction under pulsed high magnetic fields, N. Qureshi, F. Bourdarot, E. Ressouche, W. Knafo, F. Iga, S. Michimura, L.-P. Regnault, and F. Duc, Phys. Rev. B 106, 094427 (2022).
- 40-Tesla pulsed-field cryomagnet for single crystal neutron diffraction, F. Duc, X. Tonon, J. Billette, B. Rollet, W. Knafo, F. Bourdarot, J. Béard, F. Mantegazza, B. Longuet, J. E. Lorenzo, E. Lelièvre-Berna, P. Frings and L.-P. Regnault, Rev. Sci. Instrum. 89, 053905 (2018).
- “Field-induced spin-density wave beyond hidden order in URu2Si2“, W. Knafo, F. Duc, F. Bourdarot, K. Kuwahara, H. Nojiri, D. Aoki, J. Billette, P. Frings, X. Tonon, E. Lelièvre-Berna, J. Flouquet, and L.-P. Regnault, Nature Commun. 7, 13075 (2016).
XAS/XMCD:
- Field-induced magnetic transitions in the highly anisotropic ferrimagnet ErFe5Al7 studied by high-field x-ray magnetic dichroism, Yamamoto, D. I. Gorbunov, O. Prokhnenko, E. Weschke, A. Miyata, I. F. Diaz-Ortega, C. Strohm, F. Duc, M. S. Henriques, A. Gazizulina, M. Uhlarz, O. Mathon, A. V. Andreev, H. Nojiri and J. Wosnitza, Phys. Rev. B 109, 094404 (2024).
- 4f spin driven ferroelectric-ferromagnetic multiferroicity in PrMn2O5 under a magnetic field, Chattopadhyay, V. Balédent, S. K. Panda, Sh. Yamamoto, F. Duc, T. Herrmannsdörfer, M. Uhlarz, T. Gottschall, O. Mathon, Z. Wang, C. Strohm, M. Greenblatt, P. Foury-Leylekian, and J. Wosnitza, Phys. Rev. B 102, 094408 (2020).
Reviews about heavy-fermion physics:
Publications on HAL
