Electrochemically engineered chiral tellurium nanowires for spin-orbit quantum devices

Semiconductor spin qubits are a leading platform for scalable quantum computing, and a new paradigm is emerging in which the handedness of the host lattice, not just its composition, determines qubit properties. Tellurium is an archetypical example: Its atoms form helical chains that produce unusually strong spin-orbit coupling and gate-tunable charge-to-spin conversion. This allows spins confined in gate-defined quantum dots to be manipulated with electric fields alone, a route to fast, compact qubit control. Tellurium nanowires have already shown phase-coherent, quasi-ballistic transport and gate-defined quantum dots. However, tellurium crystallises in two mirror-image forms, as-grown material usually mixes both, and the spin-orbit response reverses with handedness. This is a fundamental barrier to reproducible qubits.

This project will realise enantiopure tellurium nanowires with controllable handedness as a materials platform for chiral spin qubits. Low-temperature electrochemical deposition at Southampton gives direct control over diameter, orientation, defect density and surface chemistry. Using it, we will develop templated and template-free growth routes and bias deposition towards a single handedness using chiral additives and chirally modified electrodes. Handedness will be verified by circular dichroism, Raman spectroscopy and convergent-beam electron diffraction. Wires will then be fabricated into devices in the Southampton Nanofabrication Centre and measured at cryogenic temperatures. These measurements will probe phase coherence, Coulomb blockade, g-factor anisotropy and spin-orbit energy scales, the quantities that define qubit operation, and establish how chirality governs electrical spin control.