ABSTRACT
Research regarding electron spin-based quantum bits (qubits) has primarily been performed using coupled quantum dots (QDs) in a GaAs/AlGaAs heterostructure, a system for which the spin coherence physics is well understood and fundamental technologies for controlling quantum states have been developed [1-5]. This system has a small electron effective mass, m*, (equal to 0.067m0, where m0 is the mass of a free electron) and thus, the QD size required to obtain quantum effects is relatively large (~100 nm) and can be readily obtained using electron beam lithography. However, additional research into quantum operations has found defects associated with decoherence of the electron spin. The main source of this decoherence is the hyperfine interaction with the nuclear spins of the Ga and As host materials [6].
