{"id":11865,"date":"2026-01-15T08:45:24","date_gmt":"2026-01-15T07:45:24","guid":{"rendered":"https:\/\/fermi.univ-tlse3.fr\/?post_type=tribe_events&p=11865"},"modified":"2026-01-15T15:30:09","modified_gmt":"2026-01-15T14:30:09","slug":"the-role-of-spin-fluctuations-in-quantum-materials-caitlin-duffy-lncmi-seminar-15-01-2026-14h","status":"publish","type":"tribe_events","link":"https:\/\/fermi.univ-tlse3.fr\/fr\/home\/event\/the-role-of-spin-fluctuations-in-quantum-materials-caitlin-duffy-lncmi-seminar-15-01-2026-14h\/","title":{"rendered":"The role of spin fluctuations in quantum materials. – (Caitlin Duffy \/ LNCMI \/ Seminar). – 15\/01\/2026, 14H"},"content":{"rendered":"

Seminar LNCMI<\/span><\/p>\n

Caitlin Duffy <\/strong><\/span>\u00a0<\/span><\/p>\n

Seminar LNCMI, 15\/01\/2026, 14H, seminar room and Visio<\/strong><\/span><\/p>\n

Summary<\/strong><\/span><\/span>
\nSpin fluctuations are seen as crucial in a wealth of quantum materials and have been theoretically shown to give rise to non-Fermi liquid behaviour and unconventional superconductivity [1,2]<\/strong>. However, their direct observation is a significant challenge, particularly in high magnetic fields where many correlated systems exhibit unusual behaviour.<\/p>\n

These fluctuations can be indirectly seen in high fields using techniques such as ultrasound and magnetotransport. Direct observation has recently been made possible using resonant torsion magnetometry (RTM) \u2013 a cantilever-based technique that measures spin fluctuations through the anisotropic magnetic susceptibility of a sample. RTM was developed at the NHFML in Los Alamos and has been used to observe transverse magnetic fluctuations preceding the field-induced superconducting phase of UTe2 [3]<\/strong>, and to provide support in favour of the quantum spin liquid state in RuCl3 [4]<\/strong>.<\/p>\n

In this seminar I will introduce this novel and powerful technique that I would like to bring the LNCMI. I will discuss how I aim to complement RTM studies with ultrasound and magnetotransport measurements to answer several long-standing questions about the iron pnictides and iron selenides. These two classes of strange metal both host unconventional superconductivity and quantum criticality. However, the magnetically-ordered phase present in the pnictides, and theoretically assumed to induce its unconventional behaviour, is absent in the selenides.<\/p>\n

Additionally, I will briefly mention how this technique can be of interest within the wider community of the LNCMI and the EMFL.<\/p>\n

[1]<\/strong> Kontani, Rep. Prog. Phys. 71, 026501 (2009)
\n[2]<\/strong> Scalapino, J. Low Temp. Phys. 117, 179-188 (1999)
\n[3]<\/strong> Zambra et al., arXiv:2506.08984
\n[4]<\/strong> Modic et al., Nat. Phys. 17, pages 240\u2013244 (2021)<\/p>\n

Zoom<\/strong>: https:\/\/univ-grenoble-alpes-fr.zoom.us\/j\/94228207316?pwd=khTdznxeFy1ZUYkYftQ0QSox6Fz3iK.1<\/a><\/p>\n

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