Detecting the Majorana fermion surface state of He3-B through spin relaxation

The Majorana fermion, which can be useful for topological quantum computation, has eluded detection. He3-B, recently shown to be a time-reversal invariant topological superfluid, has a gapless Majorana fermion surface state. We show here that an electron spin relaxation experiment can detect this surface state-its Majorana nature through the Zeeman field direction dependence of the relaxation time 1/T1 sin 2θ, where θ is the angle between the field and the surface normal. We propose an experimental setup where an electron inside a nanobubble is injected below the He3 liquid surface.