US 12,439,724 B2
Silicon-germanium alloy-based quantum dots with increased alloy disorder and enhanced valley splitting
Mark G. Friesen, Middleton, WI (US); Merritt Losert, Madison, WI (US); and Susan Nan Coppersmith, Redfern (AU)
Assigned to Wisconsin Alumni Research Foundation, Madison, WI (US); and NewSouth Innovations Pty Limited, UNSW Sydney (AU)
Filed by Wisconsin Alumni Research Foundation, Madison, WI (US); and NewSouth Innovations Pty Limited, Sydney (AU)
Filed on Jun. 17, 2022, as Appl. No. 17/842,988.
Claims priority of provisional application 63/214,957, filed on Jun. 25, 2021.
Prior Publication US 2023/0085706 A1, Mar. 23, 2023
Int. Cl. H10F 77/14 (2025.01); H10F 77/122 (2025.01)
CPC H10F 77/1433 (2025.01) [H10F 77/122 (2025.01)] 20 Claims
OG exemplary drawing
 
1. A gate-controlled quantum dot device comprising:
a semiconductor heterostructure comprising:
a first barrier comprising a silicon-germanium alloy or germanium;
a second barrier comprising a silicon-germanium alloy or germanium; and
a quantum well comprising a silicon-germanium alloy having random alloy disorder and a two-fold valley degeneracy at its conduction band minimum disposed between the first barrier and the second barrier, wherein the germanium concentration in the silicon-germanium alloy of the quantum well is lower than the germanium concentration in the first and second barriers; and
one or more electrostatic gates in electrical communication with the semiconductor heterostructure, wherein the one or more electrostatic gates are configured to apply a controllable potential to the quantum well, wherein the controllable potential forms at least one quantum dot comprising a confined electron in the quantum well.