Charge-noise spectroscopy of Si/SiGe quantum dots via dynamically-decoupled exchange oscillations
Abstract
Electron spins in silicon quantum dots are promising qubits due to their long coherence times, scalable fabrication, and potential for all-electrical control. However, charge noise in the host semiconductor presents a major obstacle to achieving high-fidelity single- and two-qubit gates in these devices. In this work, we measure the charge-noise spectrum of a Si/SiGe singlet-triplet qubit over nearly 12 decades in frequency using a combination of methods, including dynamically-decoupled exchange oscillations with up to 512 π pulses during the qubit evolution. The charge noise is colored across the entire frequency range of our measurements, although the spectral exponent changes with frequency. Moreover, the charge-noise spectrum inferred from conductance measurements of a proximal sensor quantum dot agrees with that inferred from coherent oscillations of the singlet-triplet qubit, suggesting that simple transport measurements can accurately characterize the charge noise over a wide frequency range in Si/SiGe quantum dots.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Feb 17, 2022
- Source ID
- 10.1038/s41467-022-28519-x
Entities
People
- Elliot J. Connors
- Jared Nelson
- John M Nichol
- Lisa F. Edge
Organizations
- Army Research Office