Technique - (30) Low-temperature transport measurements

Type: Experimental

Description: Four-probe magnetotransport, Hall effect, and conductance quantization measurements at mK temperatures.

Department(s)/lab(s): Physics – Laboratory for Solid State Physics (ETH) / PSI / EPFL | Quantum Technologies Group (Aeppli, ETH/PSI/EPFL) @ ETH Zurich
Summary:

Aeppli leads the Quantum Technologies Group spanning ETH Zurich, EPFL, and PSI. Research directions: (1) Quantum materials imaging β€” using SLS synchrotron X-rays (including SwissFEL ultrafast pulses) and neutrons at SINQ to image quantum phase transitions, skyrmions, and correlated phases; non-destructive imaging of device structures; (2) Rare-earth quantum magnets and qubits β€” LiHoF4 as a model quantum system; Er, Pr, and Nd spin qubits in crystals for quantum information and sensing; (3) Semiconductor quantum devices β€” silicon and germanium nanostructures probed by synchrotron nanoscale X-ray imaging; (4) Van der Waals materials and CDW memory devices. Strong interface with PSI large-scale facilities as unique quantum sensing tools for materials.

Department(s)/lab(s): Physics (Condensed Matter Physics Sub-department) | Quantum Spin Dynamics Group @ Oxford
Summary:

Ardavan leads the Quantum Spin Dynamics group, studying quantum coherent phenomena in condensed matter. Central to the lab's quantum sensing relevance: (1) molecular spin qubits β€” using pulsed EPR/DEER to characterise and control multi-spin registers ({Cr7Ni} molecular rings, nitroxide radical chains) assembled into qubit networks, measuring coherence times, inter-qubit couplings, and demonstrating spin-electric coupling in molecular magnets; (2) DNA-assembled molecular quantum devices β€” using DNA nanostructures to precisely position molecular spin qubits for multi-qubit sensing and quantum information applications; (3) surface atom spin resonance β€” STM-based coherent spin control of individual atoms on surfaces at nanosecond timescales. Uses X-band through W-band pulsed EPR at Centre for Advanced Electron Spin Resonance (CAESR), Oxford.

Department(s)/lab(s): School of Physics | Cassidy Quantum Devices Group @ UNSW
Summary:

Cassidy (formerly Microsoft/Sydney) builds hybrid superconductor-semiconductor quantum devices and the microwave measurement chains needed to read them out: dispersive gate sensing, superconducting resonators coupled to semiconductor nanostructures, and quantum-limited parametric amplification. The programme sits at the boundary between quantum computing hardware and quantum sensing β€” many of the same circuits used to read a qubit are, viewed differently, near-quantum-limited detectors of microwave photons or of charge. Positioned against the established body of NV-ensemble quantum sensing work β€” DEER, nanoscale NMR and T1 relaxometry protocols operating at pT/sqrt(Hz) field sensitivity β€” a superconducting-resonator readout chain with a quantum-limited amplifier is the leading route to inductively-detected spin resonance at sensitivities well below the pT/sqrt(Hz) regime accessible to optical NV ensembles, and Cassidy's group has the full stack of skills required. Mid-career, actively building; good autonomy for a postdoc.

Department(s)/lab(s): Physics – Laboratory for Solid State Physics | Hybrid Quantum Systems Group (Chu Group) @ ETH Zurich
Summary:

Chu leads the Hybrid Quantum Systems Group coupling mechanical resonators to superconducting circuits and diamond color centers. Research directions: (1) Circuit quantum acousto-dynamics (cQAD) β€” HBAR resonators coupled to transmon qubits achieve single-phonon nonlinearity (coherence/anharmonicity ratio 6.8), mechanical qubit gates demonstrated (arXiv 2406.07360, 2024); (2) Optimal control for high Fock state preparation in bulk resonators; (3) Ultra-cold mechanical quantum sensor β€” cryogenically cooled nanomechanical oscillators as probes for new physics beyond the standard model; (4) Coupling NV/SiV color centers in diamond to acoustic waves for hybrid quantum memory and transduction. Targets long-lived phonon storage for quantum networking and quantum sensing beyond the standard quantum limit.

Department(s)/lab(s): Physics – Laboratoire Kastler Brossel, Sorbonne UniversitΓ© / ENS | Optomechanics and Quantum Measurements Group (Cohadon & Heidmann / LKB) @ Sorbonne
Summary:

Cohadon and Heidmann co-lead the Optomechanics and Quantum Measurements group at LKB. Research directions: (1) Back-action evasion and Standard Quantum Limit (SQL) β€” early demonstration of radiation-pressure back-action in a micro-mirror (Nature 2006), subsequent beating of SQL via quantum correlations; (2) Micro/nanomechanical resonators β€” 2D photonic crystal deformable slabs, membrane-in-the-middle cavities, micropillar resonators for radiation-pressure optomechanics; (3) Superconducting qubit–macroscopic membrane coupling β€” Jacqmin & DelΓ©glise team: resonant coupling of transmon qubit to MHz membrane oscillator, tracking quantum motion with 300 repeated interactions (2025); high-impedance hyperinductors for electromechanics; (4) Gravitational wave detector contributions β€” VIRGO/LIGO data analysis and quantum noise modeling. Applications include back-action-evading force sensing and tests of quantum mechanics at macroscopic scales.

Department(s)/lab(s): School of Physics | Superconducting Quantum Circuits Laboratory @ USyd
Summary:

Croot returned from Princeton to found Sydney's Superconducting Quantum Circuits Laboratory. The programme uses superconducting circuits both as quantum processors and as extremely sensitive probes: coupling microwave resonators and qubits to other degrees of freedom (mechanical modes, semiconductor structures, spins) to build hybrid systems, and developing the quantum-limited amplification chain that makes single-microwave-photon detection possible. Positioned against the established body of NV-ensemble quantum sensing work β€” DEER, nanoscale NMR and T1 relaxometry protocols operating at pT/sqrt(Hz) field sensitivity β€” superconducting circuits are the principal competitor technology for detecting the weak microwave signals that NV ensembles read magnetically; a quantum-limited or squeezed microwave amplifier is what lets an inductively-detected spin ensemble reach β€” and beat β€” the pT/sqrt(Hz) regime. Newly established, well-equipped lab; high autonomy for a postdoc and active recruitment as the lab builds out.

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 β€” DEER, nanoscale NMR and T1 relaxometry protocols operating at pT/sqrt(Hz) field sensitivity β€” 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): School of Physics | Sydney Astroparticle and Dark Matter Group @ USyd
Summary:

Fruth is an experimentalist on LZ, the world-leading liquid-xenon dark matter experiment, and works on the detector-physics end: electron and single-photon backgrounds, calibration, and the characterisation of the anomalous low-energy events that currently limit sensitivity at the bottom of the energy spectrum. The programme is a pure exercise in pushing a detector's noise floor down until it is limited by irreducible physics (the neutrino fog). Positioned against the established body of NV-ensemble quantum sensing work β€” DEER, nanoscale NMR and T1 relaxometry protocols operating at pT/sqrt(Hz) field sensitivity β€” dark matter detection and NV-ensemble magnetometry are the same problem in different clothing β€” an exquisitely quiet detector, a signal below the background, and a systematics budget that determines everything β€” and the quantum-sensing community is increasingly supplying the readout technology (quantum-limited amplifiers, single-photon counters) that these experiments now need. Early-career PI.

Department(s)/lab(s): Electrical & Electronic Engineering – Photon Science Institute | Halsall Group (Photonics and Semiconductor Spectroscopy) @ Manchester
Summary:

Halsall is a senior PSI photonics researcher focusing on semiconductor spectroscopy and photonic quantum device characterization. Research directions: (1) Deep-level transient spectroscopy (DLTS) β€” characterizing defects and impurities in semiconductor quantum device structures (Si, GaN, SiC) that are relevant to qubit coherence; (2) Photoluminescence mapping β€” spatial mapping of optical quality in quantum well and dot wafers for quantum sensing device development; (3) InGaN/GaN quantum wells β€” non-destructive optical characterization of LED and sensor structures; (4) THz and infrared spectroscopy β€” contactless Hall measurements and Drude response for quantum material characterization. Provides photonic metrology tools for characterizing quantum sensing device materials.

Department(s)/lab(s): School of Physics | Quantum Electronic Devices Group (Hamilton) @ UNSW
Summary:

Hamilton heads the Quantum Electronic Devices group and is Deputy Director of the ARC Centre for Future Low Energy Electronics (FLEET). The group works on hole-based quantum devices in GaAs and germanium, where strong spin-orbit coupling allows all-electrical spin control, and on topological materials and one-dimensional transport. The measurements are millikelvin transport and noise spectroscopy of very small signals in mesoscopic devices. Positioned against the established body of NV-ensemble quantum sensing work β€” DEER, nanoscale NMR and T1 relaxometry protocols operating at pT/sqrt(Hz) field sensitivity β€” the link is indirect β€” this is charge/spin transport rather than magnetometry β€” but the group's expertise in low-noise cryogenic measurement and in spin-orbit-mediated electrical spin control is directly transferable to electrically-detected spin sensing, which is the main alternative to the optical readout that limits pT/sqrt(Hz) NV ensembles. Borderline inclusion; kept under the inclusive rubric.