Accumulation gate for quantum device
AssigneesNederlandse Organisatie voor toegepast-natuurwetenschappelijk onderzoek TNO, Technische Universiteit Delft
InventorsNodar Samkharadze, Guoji Zheng
Life of this patent
Estimating the term…
Abstract
A quantum device is described that includes a substrate with a layered structure, e.g. heterostructure, forming a quantum well layer. A doped region is connected to the layered structure for exchanging charge carriers with the quantum well layer. A patterned layer of electrically conductive material forms a set of gates including an accumulation gate. The accumulation gate comprises an accumulation pad configured to accumulate a two-dimensional charge carrier gas (2DCCG) in an active region of the quantum well layer connected there below to the doped region. At least part of an electric pathway between the accumulation pad and a connection pad is narrowed to form a nanoscale constriction for cutting off the active region of the quantum well layer.
Claims15
A quantum device comprising:
- a substrate comprising:
- a layered structure forming a quantum well layer at or below an interface of the substrate, and
- a doped region connected to the layered structure for exchanging charge carriers with the quantum well layer;
- and
- a patterned layer of electrically conductive material forming a set of gates at or above the interface of the substrate,
- wherein the set of gates comprises at least one accumulation gate comprising:
- an accumulation pad configured to accumulate there below a two-dimensional charge carrier gas (2DCCG) in an active region of the quantum well layer connected to the doped region depending on an electric field generated below the accumulation pad,
- a connection pad configured to connect a first electrode to the accumulation gate for setting an accumulation gate voltage to the accumulation pad determining the generated electric field, and
- an electric pathway between the accumulation pad and the connection pad, wherein at least part of the electric pathway is narrowed to form a nanoscale constriction for cutting off the active region of the quantum well layer below and confining the 2DCCG, below the accumulation pad, to the cut off active region;
- wherein the accumulation pad, up to the nanoscale constriction, has a surface area of at least one tenth square micrometer.
Dependencies are inferred from the claim text.