Description: Forward and backward Brillouin-Mandelstam scattering in silica microspheres and fibres at cryogenic temperatures for phonon addition/subtraction and quantum state tomography of mechanical resonators.
Eggleton directs the Institute of Photonics and Optical Science and runs one of the world's leading groups on stimulated Brillouin scattering in integrated photonic circuits — the coherent interaction of light with GHz acoustic phonons in a chalcogenide or silicon waveguide. The consequences are a chip-scale microwave photonic toolbox (ultra-narrowband filters, true time delay, RF spectral analysis), photon-phonon memory, and, through the Jericho Smart Sensing Laboratory, translation into deployed sensing platforms. 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 — Brillouin optomechanics is a distinct route to the same goal — reading a weak signal out of a high-Q, low-loss resonator at the quantum noise floor — and the group's phonon-photon coupling is strong enough that quantum optomechanical operation is now within reach. Very large, very well-resourced group with extensive industry and defence funding; a candidate would be one of many.
Merklein is the independent PI within the Eggleton group most focused on the acoustic side of Brillouin physics: he demonstrated on-chip photon-phonon memory (coherently transferring an optical pulse into a long-lived acoustic excitation and back), and works on distributed Brillouin sensing in optical fibre and on the coherent control of travelling acoustic waves in waveguides. The distributed-sensing thread is a practical, sensitivity-limited measurement problem: recovering strain and temperature along kilometres of fibre from a very weak backscattered signal. 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 — phonon-mediated storage and readout is a complementary transduction channel to spin-based sensing, and the group is now pushing toward the quantum regime where the acoustic mode must be treated as a quantum object rather than a classical one. Early-career PI (DECRA) with genuine independence inside a large group.
Vanner leads the Quantum Measurement Lab, combining experiment and theory. Key research areas: (1) Cavity quantum optomechanics — developed a theoretical framework capturing nonlinear radiation-pressure beyond the linearised approximation, showing deterministic mechanical Wigner-negativity generation; demonstrated mechanical position-squared measurements in Nature Comms (2016); thermal noise squeezing by 36 dB (Nat. Comms 2013); (2) Brillouin-Mandelstam scattering — demonstrated strong coupling to high-frequency phonons (Optica 2019); single-phonon addition/subtraction via Brillouin (PRL 2021); quantum state tomography with non-Gaussianity; (3) Hybrid quantum systems — 'displacemon' architecture (nanobeam magnetically coupled to superconducting qubit, PRX 2018) for testing objective collapse and dark matter; (4) Quantum gravity tests — proposals for testing the generalised uncertainty principle (GUP) using optomechanical protocols. UKRI QTFP fellowship.