US 12,336,438 B2
Optically transparent surface gate for a qubit memory cell
Robert Willett, Warren, NJ (US)
Assigned to Nokia Technologies Oy, Espoo (FI)
Filed by Nokia Technologies Oy, Espoo (FI)
Filed on Jan. 24, 2022, as Appl. No. 17/582,800.
Prior Publication US 2023/0240155 A1, Jul. 27, 2023
Int. Cl. H01L 23/535 (2006.01); G06N 10/40 (2022.01); G06N 10/60 (2022.01); G11C 11/44 (2006.01); H10N 60/10 (2023.01)
CPC H10N 60/128 (2023.02) [G06N 10/40 (2022.01); G06N 10/60 (2022.01); G11C 11/44 (2013.01); H10N 60/11 (2023.02)] 15 Claims
OG exemplary drawing
 
1. An apparatus, comprising:
a semiconductor substrate having a quantum-well structure corresponding to one or more memory cells, each of the memory cells having a pattern of controllable electrodes, the electrodes laterally defining a physical sequence of two or more lateral regions of the quantum-well structure joined by one or more channels; and
one or more metal surface gates on the surface of the substrate substantially covering the two or more lateral regions, the one or more metal surface gates having a thickness that enables a substantial portion of light impinging thereupon to penetrate therethrough to the surface of the substrate; and
wherein the electrodes are controllable to deplete lateral areas of the quantum-well structure of charge carriers such that a 2-dimensional droplet of the charge carriers in the quantum-well structure is localized laterally along the substrate beneath the one or more metal surface gates;
wherein the one or more metal surface gates have one or more openings, each of the one or more openings having therein a respective dot-like electrode of the pattern of controllable electrodes; and
wherein each of the one or more dot-like electrodes is not in direct electrical contact with any of the one or more metal surface gates; and
wherein each of the one or more dot-like electrodes is in direct electrical contact with a corresponding electrical overpass bridge.