Xu leads the Experimental Quantum Engineering group with a joint ETH–PSI appointment. Research directions: (1) Superconducting circuit quantum sensing — using qubits-as-sensors for detecting weak microwave signals beyond standard quantum limits, quantum non-demolition readout of photon fields; (2) Quantum error correction enabled sensing — integrating bosonic codes (cat qubits, binomial codes) into sensing protocols; (3) Quantum acoustics — coupling superconducting qubits to surface acoustic wave (SAW) resonators for hybrid quantum sensing; (4) Novel quantum hardware at PSI — leveraging PSI's infrastructure for cryogenic device fabrication and testing. Connected to the ETH–PSI Quantum Computing Hub.
Xu works on frequency-dependent squeezed-light injection for quantum-enhanced gravitational-wave detection at LIGO and on trapped-cavity atom interferometry for precision tests of fundamental physics, bridging quantum optics and atom-based inertial sensing.
Xu develops STORM and related single-molecule-localization super-resolution imaging methods, along with new fluorogenic and multiplexed labeling strategies, to visualize cellular ultrastructure at ~10-20 nm resolution. The group is actively recruiting postdocs.
Yacoby's lab develops scanning-probe quantum sensors, most notably scanning single-NV-center magnetometers and SQUID-on-tip probes, to image nanoscale magnetic textures and current flow in quantum materials at cryogenic and millikelvin temperatures. This scanning-probe approach extends the sensitivity and spatial resolution of NV ensemble quantum sensing experiments (DEER, nanoscale NMR, T1 relaxometry), which established pT/√Hz-class magnetometry, down to single-spin, nanometer-scale imaging of individual quantum materials.
Yakovlev develops label-free biomedical imaging: Brillouin micro-spectroscopy of cell/tissue viscoelasticity, impulsive stimulated Brillouin scattering, SERS and coherent-Raman diagnostics, and quantum-enhanced (photon-number-resolving, sub-shot-noise) optical imaging in collaboration with Agarwal/Scully. In the broader landscape of NV-centre ensemble quantum sensing (DEER, nano-NMR, T1 relaxometry) operating near pT/sqrt(Hz) sensitivity, this work provides the biomedical, quantum-enhanced-imaging bridge for spin-sensor bio-applications.
Yan built the first quantum gas microscope for ultracold molecules and uses programmable tweezer arrays of fermionic atoms and dipolar molecules to realize custom quantum many-body Hamiltonians (Hubbard and spin models) with single-site resolution. This is primarily a quantum-simulation platform rather than a sensing one, so it is kept as an unpreferred/borderline entry; the same site-resolved tweezer/microscope toolkit underlies emerging proposals for distributed tweezer-array quantum sensors, which is the basis for inclusion.
Uses MBE thin-film growth combined with equilibrium and non-equilibrium ARPES to sense electronic structure at material interfaces. Directions: (1) non-equilibrium photoemission (tr-ARPES) to map ultrafast electron dynamics in topological and superconducting materials; (2) MBE engineering of interfacial superconductivity and topological orders at oxide and chalcogenide interfaces; (3) light-induced phase transitions probed by ultrafast ARPES as a sensing modality for correlated electron dynamics.
Yang's experimental physical chemistry lab designs new instrumentation to track single proteins, nanoparticles, and other emitters in three dimensions in real time within complex, heterogeneous environments, including a recent time-gated two-photon platform for high-speed 3D single-particle tracking. His group applies these single-molecule tracking and orientation-resolved imaging tools to protein conformational dynamics, functional nanostructures, and active-matter systems.
Yang works on the systems-level physics of silicon spin qubits: operating qubits at elevated temperatures (above one kelvin, where cryo-CMOS control electronics can be co-integrated), valley and spin-orbit engineering, and the electrical control of spin qubits without micromagnets. The 'hot qubit' programme in particular is an engineering argument about where the classical/quantum boundary should sit in a real machine. 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 — raising the operating temperature of a spin sensor while preserving coherence is the same trade a pT/sqrt(Hz) NV ensemble makes implicitly by working at room temperature; Yang's work is the silicon community's attempt to buy back some of that convenience. Borderline inclusion — this is quantum computing rather than sensing — retained under the inclusive rubric.
Yang's group integrates optics and computation for biomedical imaging - Fourier ptychographic and lensless coded-ptychography microscopy for high-resolution wide-field imaging, and wavefront-shaping/time-reversal methods to focus light through scattering tissue for deep-tissue imaging and transcranial sensing. For context, this complements the established paradigm of NV-diamond ensemble magnetometry (Hahn-echo/DEER, nanoscale NMR, T1 relaxometry) operating near pT/√Hz sensitivity.