Exotic Negative Carriers in Liquid Helium

Abstract

We have confirmed the existence of a new negative carrier of high mobility in superfluid helium, reported by Doake and Gribbon, and determined its zero-field mobility. We suggest that it may be the negative helium ion in a small cavity in the liquid. A series of carriers with mobilities between that of the "fast" and the "normal" (electron bubble) carrier is also shown to exist.