Speaker
Description
The muon spin rotation ($\mu\text{SR}$) technique has been applied to determine the behavior of the in-plane magnetic penetration depth ($\lambda_{ab}$) in the vortex state of the unconventional superconductor Sr$_2$RuO$_4$ as a means of gaining insight into its still unknown superconducting order parameter. A recent $\mu\text{SR}$ study of Sr$_2$RuO$_4$ reported a $T$-linear temperature dependence for $\lambda_{ab}$ at low temperatures that was not identified in an earlier $\mu\text{SR}$ study. Here we show that there is no significant difference between the data in the early and recent $\mu\text{SR}$ studies and both are compatible with the limiting low-temperature $\lambda_{ab}\propto T^2$ dependence expected from measurements of $\Delta\lambda_{ab}(T)=\lambda_{ab}(T)-\lambda_{ab}(0)$ in the Meissner state by other techniques. However, we argue that at this time there is no valid theoretical model for reliably determining the absolute value of $\lambda_{ab}(T)$ in Sr$_2$RuO$_4$ from $\mu\text{SR}$ measurements. Instead, we identify the formation of an unusual square vortex lattice that introduces another constraint on candidate superconducting order parameters for Sr$_2$RuO$_4$.
| yakovlev.michael@icloud.com | |
| Funding Agency | Natural Sciences and Engineering Research Council (NSERC) of Canada |
| Supervisors Name | Jeff Sonier |
| Supervisors Email | jsonier@sfu.ca |
