Ryan H. Foote

State-conditional coherent charge qubit oscillations in a Si/SiGe quadruple quantum dot

Universal quantum computation requires high fidelity single qubit rotations and controlled two qubit gates. Along with high fidelity single qubit gates, strong efforts have been made in developing robust two qubit logic gates in electrically-gated quantum dot systems to realize a compact and nano-fabrication-compatible architecture. Here, we perform measurements of state-conditional coherent oscillations of a charge qubit. Using a quadruple quantum dot formed in a Si/SiGe heterostructure, we show the first demonstration of coherent two-axis control of a double quantum dot charge qubit in undoped Si/SiGe, performing Larmor and Ramsey oscillation measurements. We extract the strength of the capacitive coupling between double quantum dots by measuring the detuning energy shift (

Extending the coherence of a quantum dot hybrid qubit

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Electronic Transport Properties of Epitaxial Si/SiGe Heterostructures Grown on Single-Crystal SiGe Nanomembranes.

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The critical role of substrate disorder in valley splitting in Si quantum wells

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Mitigating the effects of charge noise and improving the coherence of a quantum dot hybrid qubit

eV) of one double dot depending on the excess charge configuration of the other double dot. We further demonstrate that the strong capacitive coupling allows fast conditional Landau-Zener-Stuckelberg interferences with conditonal

Signatures of atomic-scale structure in the energy dispersion and coherence of a Si quantum-dot qubit.

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Transport and valley splitting in Si quantum wells with pure Ge at the top interface

phase flip time about 80 ps, showing promising pathways toward multi-qubit entanglement control in semiconductor quantum dots.

Gating the superconducting transition in gallium doped silicon

Identifying and ameliorating dominant sources of decoherence are important steps in understanding and improving quantum systems. Here, we show that the free induction decay time (

Progress towards two double-dot qubits in Si/SiGe: quadruple quantum dots

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