Regensburg 2022 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 8: Frustrated Magnets – Strong Spin-Orbit Coupling
TT 8.7: Vortrag
Montag, 5. September 2022, 18:45–19:00, H10
Fragility of charge frustration in high-pressure CsW2O6 — •Pascal Reiss1, Masahiko Isobe1, and Hidenori Takagi1,2 — 1Max Planck Institute for Solid State Research, Stuttgart, Germany — 2Department of Physics, The University of Tokyo, Bunkyo, Tokyo, Japan
The transition metal compound CsW2O6 represents an intriguing example of a pyrochlore structure at quarter filling. Starting from a nominal W5.5+ oxidation state, the system suffers a metal-to-insulator transition around Tc ≈ 215 K where a breathing distortion leads to the formation of regular molecular W3 trimers with 2 localised electrons each, and a remaining W6+ site devoid of 5d electrons [1]. Recently, it was proposed that in this low-temperature phase, the interplay between a strong spin-orbital coupling and the transfer integral could realise a rare case of an intrinsically half-filled flat band dispersion with a stiff spin chirality [2].
In this talk, we will present our recent high pressures transport measurement on CsW2O6. With increasing pressure, we find that the low-temperature insulating phase is stabilised as the metal-to-insulator transition shifts to higher temperatures. We will discuss our results in the light of recent theoretical proposals.
[1] Y. Okamoto et al., Nat. Commun. 11 (2020)
[2] N. Nakai and C. Hotta, Nat. Commun. 13 (2022)