Fig. 4: Vortex Hall angle and vortex Reynolds number.
From: Mutual friction and vortex Hall angle in a strongly interacting Fermi superfluid
a The vortex Hall angle \({\Theta }_{H}={\tan }^{-1}\left((1-{\alpha }^{{\prime} })/\alpha \right)\) as a function of temperature, determining the deviation of the vortex velocity from the normal to the background superfluid velocity. The inset shows the estimated relaxation time τ of localized quasiparticle, normalized to the Fermi time tF = h/EF = 0.12(2) ms, determined from \(\tan {\Theta }_{H}={\omega }_{0}\tau\) by fixing ℏω0 = ∣Δ∣2/EF. b Vortex Reynolds number \({{\mbox{Re}}}_{\alpha }=(1-{\alpha }^{{\prime} })/\alpha\) as a function of temperature. The shaded gray region defines the estimated transition temperature to the laminar regime, Reα ~1. Specifically, it marks the regime of temperatures providing a value of Reα between 0.5 and 2 according to Kopnin formula Reα = ω0τ (blue line). Color code is defined in Fig. 3c–d. The error bars are obtained from the propagation of uncertainties in the quantities α and \({\alpha }^{{\prime} }\).
