Chinese Scientists Achieve Entanglement-Enhanced Nanoscale Single-Spin Quantum Sensing

According to reports from the University of Science and Technology of China (USTC), Professor Wang Ya from the Spin Magnetic Resonance Laboratory at USTC, in collaboration with the National Key Laboratory of Marine Precision Perception Technology at Zhejiang University, has made significant progress in the field of nanoscale quantum precision measurement. For the first time, they have achieved entanglement-enhanced single-spin detection at the nanoscale in a noisy environment. The related research findings were published online in the internationally authoritative academic journal Nature on November 27, Beijing time.

In the microscopic world, the "spin" of an electron is one of its fundamental properties, akin to tiny magnetic needles. Many macroscopic properties of materials, such as the magnetism of magnets or the zero resistance of superconductors, originate from the arrangement and interactions of these microscopic "magnetic needles."

The researchers explained that detecting individual spins and measuring the most fundamental magnetic units of the material world not only provides a new perspective for understanding material properties but also lays a solid foundation for developing single-molecule magnetic detection technology and advancing quantum technology. However, since matter contains a vast number of spins, detecting a single spin is equivalent to clearly capturing a specific person's whisper in a noisy stadium, posing significant challenges to the relevant technology.

The diamond nitrogen-vacancy (NV) center quantum sensor has been an important technical approach for achieving single-spin detection due to its nanoscale resolution and high magnetic sensitivity. With the long-term goal of single-spin detection, the research team, through sustained accumulation, has developed high-precision spin quantum control technology and core components and equipment for diamond quantum sensing. In prior work, they were already able to identify spins with special "markers" through spectral differences.

The researchers noted that for over a decade, the team has focused on the independent preparation of high-quality diamond quantum sensors, establishing a complete process flow covering more than twenty steps and mastering the key techniques. Through synergistic innovation in both material preparation and quantum control, they have successfully developed entanglement-enhanced nanoscale single-spin detection technology for the first time. This achievement simultaneously enhances the sensitivity and spatial resolution of microscopic magnetic signals in solid-state systems, paving the way for the continued development of nanoscale quantum precision measurement technology.