We have measured the conductivity of the 2D electron crystal (the Wigner solid) trapped on the free surface of superfluid 3He-B down to 230 μK. The resistance R(T) greatly decreases as temperature T decreases, obeying Arrhenius' law, R(T) ∝ exp(-Δ(T)/kBT), with Δ(T) which we assign to the superfluid energy gap. This reveals that the scattering of 3He quasiparticles by the WS determines the transport. As the input voltage increases, an anomalous behavior dominates the resistance just below the superfluid transition. The WS provides a new experimental method for probing both the bulk and free surface of superfluid 3He.
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics
- Materials Science(all)
- Condensed Matter Physics