911勛圖

Thesis Defense

Superconducting State in LaNiGa2 and Sr2RuO4 Single Crystals Investigated with μSR

Mikhail Yakovlev, MSc Candidate, 911勛圖 Physics
Location: P8445.2 and on Zoom

Wednesday, 03 December 2025 10:00AM PST
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Synopsis

In this work, transverse-field (TF) muon spin rotation (弮SR) technique was employed to determine the in-plane magnetic penetration depth 弇ac in high-quality LaNiGa2 single crystals. The temperature dependence of the superfluid density inferred from measurements of 弇ac(T) is well described by a two-band model with strong interband coupling, supporting a proposed internally antisymmetric, nonunitary spin-triplet state for this superconductor. This thesis also revisits two TF-弮SR studies of Sr2RuO4 that show different behaviors for the limiting low-T temperature dependence of the in-plane magnetic penetration depth 弇aband hence reach different conclusions regarding the superconducting gap structure. Here it is shown through the application of a common data analysis method that both studies are consistent with a low-temperature 弇ab T2 dependence, and are in agreement with Meissner-state measurements of 弇ab(T) = 弇ab(T) 弇ab(0) obtained by other techniques. In addition, the magnetic field profile B(r) in Sr2RuO4 is shown to be abnormal, introducing a new constraint on the possible superconducting order parameters of Sr2RuO4.

For Zoom link info, please contact Lindiwe Coyne at physgrad@sfu.ca.