Lateral heterostructure isolated coupled quantum dots

A method comprising:

• forming a semiconductor structure comprising isolated coupled quantum dots defining a physical spin qubit, wherein forming a semiconductor structure comprises:
• providing silicon-on-isolator substrate comprising a doped silicon layer atop an isolator;
• structuring said doped silicon layer to form a following structure, wherein the following structure comprises:
• a source area structure,
• a linear structure extending from said source area, wherein said linear structure has a first width which is smaller than a main area of said source area, and
• gate structures extending vertically to a main extension direction of said linear structure, wherein said gate structures are isolated from said linear structure, and wherein said gate structures define at least a first and a second gate area,
• covering said following structure with a blanket oxide layer;
• removing said blanket oxide at a lateral end of said linear structure opposite to said source area such that an opening is created in said blanket oxide;
• laterally etching back said linear structure between said blanket oxide and said isolator until an area near said source area is reached, thereby forming a hollow template between said isolator and said blanket oxide layer;
• epitaxial and laterally filling said hollow template with a first semiconductor material different to said silicon such that said hollow template is filled up to a first length extending from said source area;
• continuing said epitaxial and laterally filling said hollow template with an alternating sequence of lateral thin layers of a second semiconductor material and a third semiconductor material, such that at least two thin layers of said second semiconductor material and three thin layers of said third semiconductor material are deposited, such that said lateral thin layers of said third material are positioned in a planes, defined by said first and said second gate area;
• and
• continuing said epitaxial and laterally filling said hollow template with said first semiconductor material until an end of said hollow template is reached.