| Oct 27, 2025 |
The world's first ultra-precise, ultra-high-resolution distributed quantum sensor with 'entangled light'
Distant sensors work as one, simultaneously enhancing both precision and resolution.
(Nanowerk News) Precise metrology forms a fundamental basis for advanced science and technology, including bioimaging, semiconductor defects diagnostics, and space telescope observations. However, the sensor technologies used in metrology have so far faced a physical barrier known as "standard quantum limit".
|
|
A promising alternative to surpass this limit is the distributed quantum sensor-A technology that links multiple spatially separated sensors into a single, large-scale quantum system, thereby enabling highly precise measurements. To date, efforts have primarily focused on enhancing precision, while the potential for extending this approach to high-resolution imaging has not yet been fully demonstrated.
|
|
Dr. Hyang-Tag Lim's research team at the Center for Quantum Technology, Korea Institute of Science and Technology (KIST), has demonstrated the world's first ultra-high-resolution distributed quantum sensor network. By applying a special quantum-entangled state, known as the "multi-mode N00N state," to distributed sensors, the team achieved simultaneous enhancement of both precision and resolution (Physical Review Letters, "Distributed quantum sensing with multi-mode N00N states").
|
 |
| Distribution of quantum states generated by a central node to each node, phase encoding at each node, and estimation of arbitrary linear combinations of phases through local measurements. (Image: Korea Institute of Science and Technology)
|
|
Previous work on distributed quantum sensors has primarily relied on single-photon entangled states, which can enhance precision, but are limited for high-resolution measurements that require fine discrimination of interference patterns.
|
|
The "multi-mode N00N state" emploted by the KIST researchers involves multiple photons entangled along specific paths, producing much denser interference fringes. As a result, the resolution is significantly enhanced, while even the smallest physical changes can be detected with high sensitivity.
|
|
The technique not only approaches the "Heisenberg limit," the ultimate level of precision attainable with quantum technology, but also demonstrated potential for applications in super-resolution imaging.
|
|
This achievement is a particularly significant, as it suggests that Korea can secure international competitiveness at a time when major advanced countries, including the United States and European nations, have designated quantum sensors as a next-generation strategic technology and are making substantial investments in the field.
|
|
The team created a two-photon multi-mode N00N state entangled across four path modes and used it to simultaneously measure two distinct phase parameters. As a result, they achieved approximately 88% higher precision (2.74 dB improvement) compared to conventional methods, thereby demonstrating performance approaching the Heisenberg limit not only in theory but also in experiment.
|
|
The achievement has broad potential for applications across fields that require precision metrology, including life sciences, the semiconductor industry, precision medicine, and space observation. For instance, it could enable high-clarity imaging of subcellular microstructures that are difficult to resolve with conventional microscopes, the detection of nanometer-scale defects in semiconductor circuits, and the precise observation of distant astronomical structures that would otherwise appear blurred through ordinary telescopes.
|
|
"This achievement marks an important milestone, demonstrating the potential of practical quantum sensor networks based on quantum entanglement technology," said Dr. Hyang-Tag Lim of KIST. "In the future, when combined with silicon-photonics-based quantum chip technology, it could be applied to a wide range of everyday applications."
|
