<p>Laser physics and quantum science have fueled revolutionary developments in atomic and fundamental physics. Precise quantum state engineering has brought tens of thousands of atoms to minute-long coherence, unveiling a new regime for measurement precision. Quantum entanglement is advancing the clock performance beyond the standard quantum limit. The combination of phase-stable laser, ultrafast optics, and precision metrology also provides new tools for nuclear physics, leading to the recent breakthrough of quantum-state-resolved laser spectroscopy of thorium-229 nuclear transition. The permeation of quantum metrology to all corners of physics sparks new ideas for testing fundamental laws of nature and searching for new physics.</p>

<p><span style="color: rgb(33, 33, 33);">What determines the state of a material when light, electronic excitations, vibrations and spins become inseparable parts of the same problem? Molecular nanophotonics offers a setting in which interactions, optical driving and dissipation jointly select collective behaviour. The central object is a driven, non-equilibrium state whose correlations depend on both the material and its electromagnetic environment. Chemical synthesis provides unusual freedom to tune this competition through electronic structure, exchange coupling, and molecular geometry.</span></p><p><br></p><p><span style="color: rgb(33, 33, 33);">I will first demonstrate how extreme optical confinement produces collective dipole synchronisation in self-assembled plasmonic nanocavity networks at room temperature [1]. Molecular excitons confined within subnanometre gaps between gold nanoparticles develop long-range spatial coherence, despite disorder and ultrafast photon loss. However, spatial phase locking coexisting with temporal photon coherence that decays within approximately 10 femtoseconds, providing an experimental setting for many-body physics under strong driving and dissipation. This results in an unusual physical system which is spatially coherent, but temporally incoherent.</span></p><p><br></p><p><span style="color: rgb(33, 33, 33);">I will then discuss routes to engineer dipole-dipole interactions involving lanthanide 4f excitations and to control spin interactions in molecular spin-bearing systems [2]. These systems offer complementary handles on energy transfer, spin selection rules and optical readout. We show how interfacial spin exchange enables usually spin-forbidden triplet excitations and room-temperature phosphorescence. This unlocks new handles to tune the optoelectronic properties of materials for new LEDs and devices. </span></p><p><br></p><p><span style="color: rgb(33, 33, 33);">Building on these capabilities, I will outline experiments within our new NanoSPINEC project to test entanglement between triplets generated by singlet fission, combining independent spin manipulation with calibrated, spin-selective reaction readout. A related goal is chemically programmable quantum sensing: integrating a molecular spin, optical reporter and binding site to detect nearby spins and local interfacial dynamics. Together, these directions pose a common theoretical challenge: predicting how microscopic interactions, environmental fluctuations and measurement determine which quantum correlations survive, and whether those correlations can control exciton transport, chemical reactivity and sensing.</span></p><p><br></p><p><span style="color: rgb(33, 33, 33);">[1] Arul, R., Fowler-Wright, P., Børresen, L. et al. Coherent room-temperature dipole synchronization in plasmonic nanocavities. </span><em style="color: rgb(33, 33, 33);">Nature Nanotechnology</em><span style="color: rgb(33, 33, 33);"> </span><strong style="color: rgb(33, 33, 33);">21</strong><span style="color: rgb(33, 33, 33);">, 1230–1237 (2026).</span></p><p><span style="color: rgb(33, 33, 33);">[2] Zhu, H., Arul, R., Jiang, Z. </span><em style="color: rgb(33, 33, 33);">et al.</em><span style="color: rgb(33, 33, 33);"> Lanthanide-doped nanocrystals enable organic room-temperature phosphorescence in solution through direct triplet excitation. </span><em style="color: rgb(33, 33, 33);">Nat. Chem.</em><span style="color: rgb(33, 33, 33);"> </span><strong style="color: rgb(33, 33, 33);">18</strong><span style="color: rgb(33, 33, 33);">, 1242–1248 (2026).</span></p><p><br></p>

<p>PCS is a great platform to study science in Cambridge and the first part of the talk is about the great Prof David Tabor and connecting with top-class PhD students in the lab.</p><p>Then the difficult question is: ‘Do you want to join industry or move into Industry after attaining the Doctorate ?’ Academe has been rising fast whereas manufacturing industry is now only 8% of UK GDP. It is a tough choice.</p><p>The final concept is finding the important relevant challenges that you can utilise. My example is the GREEN POWER transition which will change Cambridge and every other community in Britain. Some initial arguments are proposed to stimulate discussion at the end of the talk.</p>