The spin of an electron confined in a semiconductor forms a natural qubit. Challenges in exploiting spin qubits for technology include controlling individual spins with high precision, protecting quantum superpositions from their environment, and high-fidelity readout. We focus particularly on carbon-based qubit devices, where hyperfine decoherence can be eliminated.

Relevant papers:

• A valley–spin qubit in a carbon nanotube

Suspended nanotubes vibrate like tiny guitar strings. Because they are so light and stiff, the quantum level spacing typically exceeds the temperature in a cryostat, making them potential embodiments of mechanical quantum oscillators. We are interested in using the coupling to electron charge and spin degrees of freedom to probe quantum superpositions of these 'macroscopic' objects containing ~100,000 atoms.

Relevant papers:

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​Integrated circuits where each functional unit is formed by only a single molecule will be the ultimate form of electronic device scaling. We measure charge transport through individual molecules in reproducible graphene-molecule-graphene transistors that operate up to room temperature. The aim of our research is to harness quantum phenomena in single molecules for real-life applications.

Relevant papers:

• Nanoscale control of graphene electrode

• Conductance enlargement in picoscale electroburntgraphene nanojunctions

Dopant atoms in semiconductors form a natural confinement potential for electrons or holes. We study the quantum mechanical properties of individual donor and acceptor atoms embedded in state-of-the-art nanoscale silicon transistors. This research focusses on the manipulation and read-out of spin- and charge-states of single dopant atoms.

Atomic clocks are among the most precise scientific instruments ever made, and are key to advanced navigation, secure communication, and radar technology. We are pursuing a new approach to create a clock that will fit on a chip. Instead of atomic vapours, we use electron and nuclear spins in endohedral fullerene molecules, whose energy levels offer an exquisitely stable frequency reference.