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 — DEER, nanoscale NMR and T1 relaxometry protocols operating at pT/sqrt(Hz) field sensitivity — 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 — and beat — the pT/sqrt(Hz) regime. Newly established, well-equipped lab; high autonomy for a postdoc and active recruitment as the lab builds out.