Spin pump for boosting spin polarization of superfluidHe3A1phase

Abstract

Mechanical pumping and filtering of spin-polarized condensate were realized in the superfluid $^{3}\text{He}$ ${\text{A}}_{1}$ phase by the pneumatic pumping action of an electrostatically actuated diaphragm. Spin pumping increased the net spin polarization by $20--50\text{ }%$ as measured by the induced pressure change during spin pumping. The observed spin relaxation time was consistent with the increased spin polarization. These observations demonstrate the feasibility of using spin pumping to substantially increase the effective magnetic field to which the ${\text{A}}_{1}$ phase is exposed.