Master Defense

Billy Jun Ming Lim

Towards n-Parity Protected Superconducting Qubits using 2D Electron Gas

Quantum computers has long promised to revolutionise the way we view information. However, the superconducting qubits commonly touted by the big technology companies have always suffered from debilitating errors. To remedy this, many have turned to reducing the sources of errors, but few have considered reducing the qubit's sensitivity instead. This complementary approach was recently attributed with helping the fluxonium achieve its sudden leap forward in coherence times. However, the question then arises if we can achieve the same insensitivity or protection in other qubits.

In this thesis, we investigate the -parity protected qubit, which uses a π-periodic Josephson element to achieve similar protection against  relaxation, while distinctively remaining in the integer number of Cooper pairs regime. We introduce how this π-periodic Josephson element can be achieved in SNS junctions, and document the ongoing process of realising such a protected qubit in a scalable 2DEG platform.

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