Triple quantum dot device designed for three spin qubits

Electron spin confined in quantum dots is a promising candidate for experimental qubits. Aiming at realizing a three spin-qubit system, we designed split micromagnets suitable for the lateral triple quantum dots. From numerical simulations of the stray magnetic field distribution, field gradients similar to 0.8 T/mu m and differences of in-plane components similar to 10 mT can be attained, which enable the electrical and addressable manipulation of three qubits. Furthermore, this technique can be applied for up to 25 qubits in realistic multiple quantum dots. For the first step of implementing such three-qubit systems, a relevant triple quantum dot device has been fabricated and characteristic charge states were observed. (C) 2010 American Institute of Physics. [doi:10.1063/1.3518919]