Understanding and characterizing noise and variability of spin qubits

The realization of quantum computing requires the use of a very large number of qubits. Spin qubits are the most compact ones and their manufacturing is based on existing microelectronic processes. These make them very good candidates for realizing useful quantum processors.

Their functioning is affected by the noise that is present in their environment, The presence of electric field noise significantly degrades the qubit performance. There are a lot of factors influencing decoherence. Stray charges, switching dipoles, interface roughness, valley splitting, variation of Landé factor g, strain, electric signal distortion, unwanted magnetic field gradients, superconductivity in the gates, all play a role in the interaction between the qubit and its noisy environment. The objective of this project is to quantify the noise effect and propose relevant metrics to describe it. The project will go beyond coherence time and fidelity that are not the ideal ones as they vary significantly throughout the sample  Also, an outcome should be the understanding of the effects of various parameters on the performance of qubits. The student will perform theoretical calculations and use them as an input for improving the qubit design and architecture of electron spin-based quantum processors with the goal of improving future error correction schemes.