DQMP Seminar - Dr. Zurab Guguchia, PSI

06.02.2024 13:00 – 14:30

Probing Chiral Charge Order and Superconductivity in Kagome-Lattice Systems with Muon Spin Rotation
Zurab Guguchia, Paul Scherrer Institute

Kagome lattices stand at the forefront of research due to their fascinating interplay of topology, correlations, and magnetism [1-4]. Their special geometry enables various quantum phenomena, such as frustration and correlated orders, and features an electronic structure with flat bands, van Hove singularities, and Dirac cones. This makes them a prime subject for both experimental and theoretical research, offering insights into complex physical properties and potential technological applications.
In my presentation, I aim to shed light on the latest experimental developments concerning superconductivity and the magnetic aspects of charge order in various kagome-lattice systems, examined from the perspective of local magnetic probes. This involves the use of muon-spin rotation under extreme conditions like hydrostatic pressure, uniaxial strain, ultra-low temperatures, and high magnetic fields. Key systems under discussion will include: (1) The AV3Sb5 (A = K, Rb, Cs) compound series with V kagome lattice, notable for displaying a range of symmetry-breaking electronic orders, such as charge order and superconductivity. Here, we have identified a depth-tunable, time-reversal symmetry-breaking state associated with charge order, as well as tunable unconventional superconductivity [5-8]. (2) The bilayer kagome material ScV6Sn6, where hidden magnetism within the charge-ordered state was observed [9]. (3) The LaRu3Si2 system, characterized by its Ru kagome layers, in which we identified two distinct types of charge order, with one manifesting above room temperature [10]. This finding marks the first instance of observing a charge-ordered state at or above room temperature in a correlated kagome lattice.

[1]I. Syozi, Prog. Theor. Phys. 6, 306 (1951).
[2]S. Sachdev Phys. Rev. B 45, 12377 (1992).
[3]J.-X. Yin et. al., Nature Physics 15, 443 (2019).
[4]Z. Guguchia et. al., Nature Communications 11, 559 (2020).
[5]C. Mielke III et. al., and Z. Guguchia, Nature 602, 245 (2022).
[6]Z. Guguchia et. al., Nature Communications 14, 153 (2023).
[7]Z. Guguchia et. al., NPJ Quantum Materials 8, 41 (2023).
[8]J.N. Graham et. al., and Z. Guguchia, in preparation.
[9]Z. Guguchia et. al., Nature Communications 14, 7796 (2023).
[10]I. Plokhikh et. al., and Z. Guguchia, arXiv:2309.09255 (2023).

Organisé par : Prof. von Rohr

Lieu

Bâtiment: Ecole de Physique

Auditoire Stückeberg

entrée libre