  We predict a new quantum electronic structure at the interface between two
condensed phases of noble-gas elements: solid neon and superfluid helium. An
excess electron injected onto this interface self-confines its wavefunction
into a nanometric dome structure whose size varies with pressure. A collection
of such electrons can form a classical Wigner crystal visualizable by
mid-infrared photons. The ultralong spin-coherence time allows the electrons in
this system to serve as perfect quantum bits. They can be deterministically
arranged on-chip at a spacing of several microns. Their spin states can be
controlled and readout by single-electron devices. This unique system offers an
appealing new architecture for scalable quantum information processing.

Mesoscale and Nanoscale Physics;Quantum Physics