Precisely ordered quantum dot array formed using AFM lithography for all‐optical electron spin quantum computers

Abstract

For application of quantum dots (QDs) in quantum computers, a precise control of self-assembled QDs was achieved in position and size. On a GaAs surface, atomic force microscope lithography is performed to fabricate nano-scaled oxide dots. When the oxide dots are suitably detached from the substrate, holes of the same size are formed. By overgrowing InGaAs on such a hole-patterned surface, one single quantum dot, whose size depends on the hole, is formed on the site of each hole. An ordered array of differently sized QDs can be fabricated as the qubits of all-optical quantum computer using electron spins of coupled QDs.