Martin Wood Complex, Department of Physics, University of Oxford, Parks Road, Oxford, OX1 3PU
Dr Greg Mazur, Department of Materials, University of Oxford
Prof. Amalia Coldea
Abstract
Majorana zero-modes (MZMs) are predicted to be hosted at the edges of one-dimensional p-wave superconductors. MZMs can be characterized as spinless, chargeless and zero-energy excitations. Interest in MZMs has been driven by their potential applications in quantum computing, where high-fidelity gates are expected to be achieved, and quantum information can be protected from decoherence. Various platforms where MZMs might be hosted have been proposed, including topological insulators, semiconducting nanowires with strong spin-orbit interaction, iron-based superconductors, and fractional quantum Hall systems. However, conclusive experimental evidence has not been obtained.
A bottom-up approach has recently been introduced, wherein quantum dots in semiconductors with strong spin-orbit coupling have been coupled through superconductors to create a unit cell of the Kitaev chain[1,2]. Pairs of fine-tuned MZMs can be generated even in such minimal units, through which their properties can be studied [3].
In this talk I will present an experimental approach to the engineering of basic Kitaev chain components in a semiconductor/superconductor hybrid based on InSb nanowires with aluminum half-shells. I will discuss results on chain scaling [4] along with future experiments through which quantum information applications might be implemented using this platform.
[1] Wang, G., Dvir, T., Mazur, G. P., Liu, C. X., van Loo, N., Ten Haaf, S. L., ... & Kouwenhoven, L. P. (2022). Singlet and triplet Cooper pair splitting in hybrid superconducting nanowires. Nature, 612(7940), 448-453.
[2] Dvir, T., Wang, G., van Loo, N., Liu, C. X., Mazur, G. P., Bordin, A., ... & Kouwenhoven, L. P. (2023). Realization of a minimal Kitaev chain in coupled quantum dots. Nature, 614(7948), 445-450.
[3] Leijnse, M. and Flensberg, K., 2012. Parity qubits and poor man's Majorana bound states in double quantum dots. PRB, 86(13), p.134528.
[4] Bordin, A., Liu, C. X., Dvir, T., Zatelli, F., ten Haaf, S. L., van Driel, D., ... & Mazur, G. P. (2024). Signatures of Majorana protection in a three-site Kitaev chain. arXiv preprint arXiv:2402.19382.