The effect of 3He impurities on the nonclassical response to oscillation of solid 4He

TL;DR

This study explores how 3He impurities affect the nonclassical rotational inertia in solid 4He, revealing that increased 3He concentration broadens and shifts the transition temperature, indicating a link to 3He atom condensation on dislocation networks.

Contribution

It demonstrates the impact of 3He impurities on the supersolid transition in solid 4He, highlighting the role of impurity-induced disorder in the phenomenon.

Findings

Higher 3He concentration broadens the transition

Transition shifts to higher temperature with more 3He

Impurities likely cause 3He condensation on dislocation networks

Abstract

We have investigated the influence of impurities on the possible supersolid transition by systematically enriching isotopically-pure 4He (< 1 ppb of 3He) with 3He. The onset of nonclassical rotational inertia is broadened and shifts monotonically to higher temperature with increasing 3He concentration, suggesting that the phenomenon is correlated to the condensation of 3He atoms onto the dislocation network in solid 4He.