29 August 2022
Copenhagen University- Frederiksberg campus
Europe/Copenhagen timezone

Correlated charge noise in Si/SiGe quantum dot spin qubits

29 Aug 2022, 14:40
25m
A1-05.01 (Copenhagen University- Frederiksberg campus)

A1-05.01

Copenhagen University- Frederiksberg campus

Dyrlægevej 100, 1870 Frederiksberg

Speaker

Juan Rojas-Arias (RIKEN)

Description

Electron spin qubits in silicon quantum dots are particularly promising candidates for the implementation of a large-scale quantum computer due to their small physical footprint. However, this compactness raises concerns on the existence of spatial noise correlations that can be severely detrimental for quantum error correction. In this talk, I will show our results on noise spectroscopy of two neighboring qubits in a device made of isotopically purified silicon, where we detect strong noise cross-correlations. These inter-qubit correlations arise from the dominant effect of charge noise in our system, verified by the presence of noise correlations between the bare qubit frequencies and exchange interaction. We devised a simple model of electric fields shifting the position of the qubits within a magnetic field gradient, that allows us to quantitatively reproduce the measured behavior. Our work shows that electrical noise not only limits single-qubit dephasing but can also be a source of correlated phase errors.

Presentation materials

There are no materials yet.