Mouzhe Xie

In the Experimental Quantum BioSensing (EQuBS) laboratory led by Prof. Mouzhe Xie, our primary research focus is to develop novel quantum sensing technologies and apply them to better understand chemical reactions and biological processes. A leading sensor platform is the nitrogen-vacancy (NV) defect in diamond crystal, which serves as a quantum bit (or "qubit"). The preparation and manipulation of the NV qubit is achieved through an interplay of laser and microwave. Unlike other qubit systems that requires stringent experimental conditions, the NV qubit possesses micro- to milli-second long coherence at room temperature and ambient environment, making them readily applicable to investigate biological systems at molecular level.

The NV-based quantum sensor is exquisitely sensitive to several physical quantities, such as magnetic field, temperature, and crystal strain. It enables various powerful detection schemes to investigate samples of interest, including optical relaxometry, double electron-electron resonance (DEER), and optically detected magnetic resonance (ODMR). Moreover, because of the high sensitivity, the NV-based quantum sensor can detect the magnetic field fluctuations generated by single molecules and has been used to perform nanoscale NMR experiments. The NV-based quantum sensing and metrology is a burgeoning research field with lots of unknowns, and of course, opportunities.

Our research combines chemistry, physics, biology, engineering, and material science, and is multidisciplinary by nature. For example, we create high-quality NV-doped diamond material, and build laser microscopes and microwave antennas to control the spin dynamics of the NV qubit following a fundamental understand of its quantum properties. We chemically functionalize diamond surfaces and place molecules or cells on top for their detection. We also nanofabricate microchips and flow channels for integrated biological sample delivery. Conventional NMR, AFM, light and electron microscopy, X-ray, single-molecule techniques, and molecular biology tools are frequently used to help us understand biological systems better, with a goal of deciphering molecular interactions and cellular processes, and ultimately improve human health.