Quantum sensing is a new quantum technology that utilizes quantum coherence for ultrasensitive detection. It is particularly useful for sensing weak signals in nanoscale measurements. Similar to quantum computation, quantum sensing relies on initialization, control, and readout of quantum bits (i.e., qubits). While practical quantum computation needs control of many physical qubits, quantum sensing requires control and measurement of only one or a few qubits. Construction, control, and measurement of few-qubit systems have been demonstrated feasible in many physical systems, thanks to the foundational research for quantum computation. In particular, certain qubit systems (e.g., defect spins in diamond) have been shown to possess excellent quantum coherence even at room temperature and in coupling with complex environments (such as in live cells). Therefore quantum sensing is highly promising to be practically applicable in the near future. Quantum sensing will offer unprecedented sensitivity and resolution of measurement in a broad range of frontier studies, such as condensed matter physics in nano-systems, nanoscale magnetic resonance imaging, cellular dynamics in single cells, and even brain science.

The research of quantum sensing will involve cross-disciplinary efforts. The technology relies on good quantum coherence of qubits and hence critical is research on discovery and engineering of novel quantum materials and advanced quantum control protocols. Quantum sensing is to explore a broad range of target systems with unprecedented sensitivity, resolution, and/or flexibility. The target systems, often of nanometer sizes, can be of very different natures, being magnetic, electrical, mechanical, thermal chemical, or biological. Therefore the research of quantum sensing calls on not only knowledge of various disciplines (condensed matter physics, biology, chemistry, nanotechnology, and quantum physics, of course) but also expertise on integration of such a broad range of target systems and quantum sensors. Such multi-disciplinary research will be very challenging but nonetheless very rewarding. We expect this newly established GRC on Quantum Sensing will be a platform to coordinate the global efforts to tackle the grand challenges in this field.

We, in a city of a fantastic hybrid of eastern and western cultures, are looking forward to meeting you, the world leaders in quantum sensing, the young generations joining the field, and the interested from other fields looking for new research tools.