Giant viscosity enhancement in a spin-polarized Fermi liquid

Abstract

The viscosity is measured for a Fermi liquid, a dilute ${}^3$He-${}^4$He mixture, under extremely high magnetic field/temperature conditions ($B\le 14.8$ T, $T\ge 1.5$ mK). The spin splitting energy $\mu B$ is substantially greater than the Fermi energy $k_B{T}_F$; as a consequence the polarization tends to unity and s-wave quasiparticle scattering is suppressed for $T\ll T_F$. Using a novel composite vibrating-wire viscometer an enhancement of the viscosity is observed by a factor of more than 500 over its low-field value. Good agreement is found between the measured viscosity and theoretical predictions based upon a $t$-matrix formalism.

4 pages, 4 figures