Multiphysics Simulation & Design of Silicon Quantum Dot Qubit Devices

• Published in: 2019 IEEE International Electron Devices Meeting (IEDM) pp. 39.5.1 - 39.5.4
• Main Authors: Mohiyaddin, F. A., Chan, BT, Ivanov, Ts, Spessot, A., Matagne, P., Lee, J., Govoreanu, B., Raduimec, I. P., Simion, G., Stuyck, N. I. Dumoulin, Li, R., Ciubotaru, F., Eneman, G., Bufler, F. M., Kubicek, S., Jussot, J.
• Format: Conference Proceeding
• Language: English
• Published: IEEE 01-12-2019
• ISSN: 2156-017X
• DOI: 10.1109/IEDM19573.2019.8993541

In this paper, we combine multiphysics simulation methods to assemble a comprehensive design methodology for silicon qubit devices. Key device parameters are summarized by modeling device electrostatics, stress, micro-magnetics, band- structure and spin dynamics. Based on the models, we infer that highly confined single electron qubits in quantum dots, with large orbital energy separations, can be induced in Si-MOS structures with thin (t OX <; 20 nm) gate oxides. We further advocate that poly-silicon gate material, in conjunction with small barrier gate widths (b <; 30 nm), will reduce the impact of strain on qubit readout and two-qubit gate-operations. We optimized a micromagnet design to provide fast single-qubit gate times (~100 ns), with minimal dephasing field gradients. Finally, we estimate that the exchange coupling between qubits is tunable by over 4 orders of magnitude, for two-qubit operations.