Evidence for a New Phase of SolidHe3

Abstract

Measurements of the melting pressure of a sample of ${\mathrm{He}}^3$ containing less than 40-ppm ${\mathrm{He}}^4$ impurities, self-cooled to below 2 mK in a Pomeranchuk compression cell, indicate the existence of a new phase in solid ${\mathrm{He}}^3$ below 2.7 mK of a fundamentally different nature than the anticipated antiferromagnetically ordered state. At lower temperatures, evidence of possibly a further transition is observed. We discuss these pressure measurements and supporting temperature measurements.