August 30, 2024 -- Researchers worldwide are on the hunt to capture coherence, a unique and powerful feature of quantum mechanics in which individual particles like electrons or packets of light called photons sync up and behave as a larger whole. But observing such particles as they pair has been no easy feat with conventional microscopes based on classical physics principles. A quantum nano-scope is needed, and Columbia is preparing to build it.

With the support of a new $1 million Major Research Instrumentation Award from the National Science Foundation (NSF), a team led by Higgins Professor of Physics Dmitri Basov will develop a quantum scattering near-field optical microscope (q-SNOM) at Columbia.

Current SNOMs can resolve structures much smaller than wavelengths of visible light, which are relatively long, but the microscopes use classical photons that cannot capture the quantum nature of interactions between light and a material. Columbia’s quantum version will push spatial resolutions to observe just one photon at a time. This will allow researchers to work with the single photons and photon pairs that give rise to quantum coherence.

“We have already demonstrated the feasibility of many elements of this entirely novel concept, so now, with dedicated funding from the NSF, it is time to complete the project and make previously impossible inquiries into quantum materials,” said Basov.

The team anticipates that the q-SNOM, which will be able to resolve subtle electronic properties in response to quantum light, will be valuable for scientists studying the properties of molecular systems, quantum emitters (also known as quantum dots), and on-chip correlated photon waveguides.

Once operational, the q-SNOM will be housed with the Columbia Nano Initiative (CNI) on Columbia’s Morningside campus. There, it will be available as a shared-use tool to Nano Initiative lab users from Columbia and around New York City, including those from academic partners like Stony Brook University and users from private industry.