  Nonpolar atoms or molecules with light particle mass and weak
particle-particle interaction can form quantum liquids and solids (QLS) at low
temperatures. Excess electrons can be naturally bound to the surface of a QLS
in a vacuum and exhibit unique quantum electronic behaviors in two and lower
dimensions. In this article, we review the historical study and recent progress
in this area. The main topics covered in this review include the collective and
individual electron transport on liquid helium, solid neon, and solid hydrogen,
the theoretical proposal and experimental effort toward single electron qubits
on superfluid helium, the recent experimental realization of single electron
charge qubits on solid neon and the related theoretical calculation. In the
end, we review and envision extended exploration of quantum electronics on
heterogeneous QLS.
