Exchange Control in a MOS double quantum dot made using a 300mm wafer process

Exchange driven oscillations between |↓↑⟩ and |↑↓⟩ states, measured rf-phase response proportional to singlet probability

In our latest paper, our team have demonstrated exchange control, which forms the basis for two-qubit gates between spin qubits, in an MOS Double quantum dot device fabricated using a 300 mm wafer metal-oxide-semiconductor (MOS) process. The quality of the manufacturing manifests in low detuning noise and relatively long T2 for natural silicon in a MOS device. These results highlight the benefits of industrial manufacturing and encourage follow-up studies in isotopically enriched Si samples with larger numbers of quantum dots.

Alongside, the team also introduce a dispersive readout technique, the radio-frequency electron cascade, that amplifies the signal while retaining the spin-projective nature of dispersive measurements. The technique also expands the portfolio of rf readout methods and provides a solution to the relatively low sensitivity of in−situ dispersive sensing in planar MOS devices. These results enable enhanced-signal dispersive readout over long distances within dense quantum dot arrays.

These results demonstrate an industrial grade platform for two-qubit operations, alongside integration with dispersive sensing techniques.

This work included contributions from: Jacob Chittock-Wood, Ross Leon, Michael Fogarty, Tara Murphy, Sofia M. Patomäki, Giovanni A. Oakes, Felix-Ekkehard von Horstig, Nathan Johnson (UCL), Julien Jussot (IMEC), Stefan Kubicek (IMEC), Bogdan Govoreanu (IMEC), David Wise,M. Fernando Gonzalez-Zalba,and John J. L. Morton.

ArXiv paper: https://arxiv.org/abs/2408.01241