Majorana Fermions: Direct Observation in 3He

TL;DR

This paper reports the first direct detection of gapless Majorana quasiparticles on the surface of superfluid helium-3 B phase, achieved through precise heat capacity measurements at ultra-low temperatures, revealing Majorana fermions as significant heat carriers.

Contribution

It provides the first direct observation of surface Majorana quasiparticles in superfluid helium-3, distinguishing their heat capacity contribution from bulk quasiparticles.

Findings

Majorana quasiparticles constitute half of the heat capacity at 0.11 mK.

Surface Majorana states are directly observed as Andreev bound states.

The heat capacity of Majorana fermions is separated from bulk contributions based on temperature dependence.

Abstract

In this letter we report the first direct observation of gap-less Majorana QPs which appear as Andreev bound states on the surface of superfluid $^3$He-B. We made the precise measurements of superfluid 3He-B heat capacity at the limit of extremely low temperatures. We have separated the heat capacity of bulk Bogolyubov QPs and the surface Majorana QPs by its different temperature dependence. We have found that at 0.11 mK the Majorana fermions constitute half of the bolometer heat capacity under the conditions of our experiments.