Seminar: Hubert Lam

Magnetic noise - The problem child in quantum technology

Abstract
Magnetic fields are widely used in the emerging field of quantum technology but along their diversity comes on the other hand a crucial disadvantage. Quantum systems susceptible to magnetic fields are vulnerable to random magnetic fluctuations, hence magnetic induced errors. From here two fundamental approaches are possible, either by just stop using magnetic interactions at all or by suppressing the magnetic noise. Both approaches have their own physical as well as technical challenges. This talk is examining the former by considering spin qubits trapped by phosphorus donors in silicon; especially the control of the spin qubit in near magnetic free systems; and for the latter by considering Zeeman qubits of 40Ca+ trapped in a linear Paul trap; how to mitigate the influence of the magnetic noise passively and actively.