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.

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.