Optically Transparent Surface Gate for a Qubit Memory Cell

A qubit memory cell having a thin, optically transparent, metal surface gate that laterally fits into the corresponding region of the memory cell, while not being in direct contact with the perimeter of the region. The surface gate may have apertures to accommodate therein the dot-like control electrodes of the qubit and enable the corresponding electrical overpass bridges to be connected to those dot-like control electrodes. The thickness of the surface gate may be selected such as to let a substantial portion of light impinging thereupon penetrate to the underlying surface of the substrate. In at least some embodiments, the electrical-interconnect structure of the memory cell may be designed to enable separate electrical biasing of the surface gate, e.g., independent of the electrical biasing of some other electrodes of the memory cell. Advantageously, such a surface gate may significantly reduce detrimental clumping of charge carriers in the memory cell.