Research Areas - (4) Atomic Single-Electron Transistor Potential Imaging

Full path: Physics > Quantum Sensing > Scanning Probe Electrometry > Atomic Single-Electron Transistor Potential Imaging

Department(s)/lab(s): School of Electrical Engineering and Telecommunications | Dzurak Silicon Quantum Devices Group @ UNSW
Summary:

Dzurak leads the silicon CMOS quantum dot spin qubit programme at UNSW and co-founded Diraq, the company commercialising it. The group demonstrated the first silicon MOS qubit, two-qubit logic in silicon, and has pushed toward fidelities above the fault-tolerance threshold in industrially-manufactured CMOS devices, including work on gate-stack engineering for low charge noise and on single-electron-transistor charge sensing for readout. 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 — the relevant transferable asset is the readout: the single-electron-transistor and gate-based dispersive sensors this group builds are among the most sensitive electrometers in existence, the charge-domain analogue of pT/sqrt(Hz) magnetometry. Caveat against the stated preference: the programme is now heavily fabrication- and yield-driven and closely tied to a commercial roadmap, so a sensing-focused postdoc would be somewhat off the group's main axis.

Department(s)/lab(s): Physics | Klein Lab @ UChicago
Summary:

Klein pairs van der Waals heterostructure fabrication with a cryogenic scanning-probe 'Atomic Single Electron Transistor,' built on a quantum-twisting-microscope platform, to directly image sub-moire electrostatic potential landscapes with ultrasensitive, high-spatial-resolution electrometry. This is an unpreferred/borderline quantum-sensing inclusion: the sensor is an SET-based electrometer rather than an NV-ensemble magnetometer (which reaches pT/sqrt(Hz) via DEER/NMR/T1 protocols), but it shares the goal of pushing single-defect-level sensitivity for imaging quantum materials.

Department(s)/lab(s): School of Physics | Rogge Single Dopant Spectroscopy Group @ UNSW
Summary:

Rogge (formerly Delft) works on the spectroscopy of individual dopant atoms in silicon: using transport, STM and microwave spectroscopy to read out the orbital, valley and spin structure of single donors and acceptors, including their coupling to strain, electric fields and each other. The group has mapped the wavefunctions of individual dopants and used acceptor spin-orbit coupling for electric-field-driven spin control. This is single-quantum-object measurement rather than device engineering. 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 — single-donor spectroscopy is the silicon analogue of single-NV work: the same questions about coherence, bath engineering and readout fidelity that fix pT/sqrt(Hz) ensemble performance appear here in a platform where the sensor can be placed with atomic precision and interrogated electrically rather than optically.

Department(s)/lab(s): School of Physics | Atomic Fabrication Facility (Simmons) @ UNSW
Summary:

Simmons pioneered atomic-precision fabrication in silicon: hydrogen-resist STM lithography, phosphine dosing and epitaxial silicon overgrowth to place individual dopant atoms with sub-nanometre accuracy, then measure them at millikelvin. The programme has produced single-atom transistors, precision dopant arrays used as analogue quantum simulators, and the largest atom-scale device platform in the world; she also founded Silicon Quantum Computing Pty Ltd. The sensing-relevant capability is the single-electron transistor as an exquisitely sensitive electrometer, capable of resolving individual charge transitions and mapping local electrostatic potential at the atomic scale. 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 — her SET electrometry is the charge-domain counterpart to magnetic NV sensing at pT/sqrt(Hz): both are single-quantum-object detectors whose performance is limited by back-action and by the noise of the readout chain. Very large group, strongly fabrication-oriented and commercially entangled, which cuts against the stated preference for sensitivity-limited rather than fabrication-limited work.