Research Areas - (2) Single-Donor Nuclear Spin Qudits in Silicon

Full path: Physics > Quantum Information / Computing > Spin Qubits > Single-Donor Nuclear Spin Qudits in Silicon

Arne Laucht 🔗
University of New South Wales 🔗
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Department(s)/lab(s): School of Electrical Engineering and Telecommunications | Laucht Quantum Control and 2D Materials Group @ UNSW
Summary:

Laucht works on the quantum control of spins across two platforms: donor spin qubits in silicon (with Morello and Dzurak), where he demonstrated electrically-driven single-spin control in a continuous microwave field and pioneered dressed-state protection against decoherence; and, more recently, spin defects in hexagonal boron nitride — a 2D material whose optically addressable spin defects are the most promising candidate for a van der Waals analogue of the NV centre, with the enormous advantage that the sensor can be placed a single atomic layer from the sample. Positioned against the established body of NV-ensemble quantum sensing work — DEER, nanoscale NMR and T1 relaxometry protocols operating at pT/sqrt(Hz) field sensitivity — hBN spin defects are the field's most active attempt to beat the standoff-distance limitation that caps near-surface NV ensemble sensitivity; a candidate with NV ODMR experience would be immediately productive here, running the same pulse sequences on a new defect. Strong fit.

Andrea Morello 🔗
University of New South Wales 🔗
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Department(s)/lab(s): School of Electrical Engineering and Telecommunications | Fundamental Quantum Technologies Laboratory (Morello) @ UNSW
Summary:

Morello heads the Fundamental Quantum Technologies Laboratory and is the person who first read out the spin of a single electron, and then a single nucleus, in silicon. Current directions: high-spin donors (antimony-123, with eight nuclear levels) used as qudits and as sensors of local strain and electric field; nuclear acoustic resonance, in which a strain wave rather than a magnetic field drives the nuclear spin; engineered decoherence experiments as tests of quantum foundations; and precision tomography of multi-qubit donor registers. The group's donors are among the longest-coherence solid-state spins known (seconds for nuclei). Positioned against the established body of NV-ensemble quantum sensing work — DEER, nanoscale NMR and T1 relaxometry protocols operating at pT/sqrt(Hz) field sensitivity — a single-donor nuclear spin in silicon is functionally an NV centre with better coherence and worse readout: the same DEER, dynamical-decoupling and nuclear-register protocols apply, and the group's high-spin qudit work is aimed at exactly the multi-level sensing enhancements that the NV community is now chasing. Preferred attribute present: sensitivity and coherence, not fabrication, are the limiting variables here.