February 25, 2026 -- The world is never really at rest. Even in a vacuum near ultracold temperatures where all classical motion should come to a halt, you’ll find quantum fluctuations. In thin, two-dimensional materials, these include random vibrations that can alter electromagnetic fields, a feature that theorists have posited could be quite useful for modifying materials.

“It’s a holy grail we’ve been searching for decades,” said Dmitri Basov, Higgins Professor of Physics at Columbia. “We believe we’ve found it.”

In a new paper published today in Nature, Basov and 32 collaborators from 17 institutions came together to confirm that quantum fluctuations alone from the vacuum inside atom-thin layers of 2D materials can alter the properties of a larger nearby crystal—a theoretical possibility now experimentally realized for the first time.

The team, led by Columbia postdoctoral fellows Itai Keren, Tatiana Webb, and Shuai Zhang, placed a nanometer-sized flake of hexagonal Boron nitride (hBN) on top of the superconducting material κ-(BEDT-TTF)₂Cu[N(CN)₂]Br, or κ-ET, for short. With no added lasers or other external driving forces, superconductivity came to a halt.

That’s not exactly the result those seeking to enhance lossless electrical flow are looking for, but it’s an important proof of concept. “Any new knob that people can find for tuning superconductivity is significant,” said Keren.

The quantum fluctuations found between the layers of hBN vibrate at a characteristic resonance that just so happens to match that of κ-ET. “That was our intuition: if the vibrations match, they should interact with each other,” said Keren. As the two interact, the electromagnetic environment in κ-ET crystal changes in a way that impedes the movement of its electrons, preventing them from reaching a collective, superconducting state.  When they tested hBN against a superconductor with a different set of resonances, nothing happened.

The idea first germinated years ago in Central Park. During visits to New York, theoretical collaborator Angel Rubio from the Max Planck Institute for the Structure and Dynamics of Matter in Hamburg explained the potential of quantum fluctuations to a, at the time, skeptical Basov. “I thought his proposal was impossible, but it was so appealing, it was impossible not to try,” Basov recalled.

The question was how, but waiting in his nano-optics lab was hBN—a solution, waiting for its problem.

hBN has become a workhorse in a number of industrial and experimental applications, but as an inert, insulating spacer. But beginning in 2014, Basov’s lab began observing interesting optical properties in hBN that, as his conversations with Rubio continued over the years, made it an enticing candidate for a cavity.

A cavity is a structure that confines light and other electromagnetic waves. If no waves are present, it is, in a sense, a vacuum—but that doesn’t mean it’s a totally empty void. Cavities still host quantum fluctuations. Conventionally, mirrors have been used to create cavities, but quantum fluctuations strengthen as cavities shrink. Nano-scale thick sheets of hBN are about as small as it gets.

Using specialized scanning near-field optical microscopes (SNOMs), Zhang, now an assistant professor at Fudan University, and other members of Basov’s lab have confirmed over the years that vibrating quasiparticles arising inside layers of hBN can interact with and modify vibrations in other crystals, including superconducting κ-ET. But SNOMs are optical tools that rely on photons—light-carrying particles that can also modify materials. To prove what quantum fluctuations by themselves were capable of, Basov needed a way to work in the dark—literally.

Co-author and fellow Columbia physicist Abhay Pasupathy had just the dark probe: a cryogenic magnetic force microscope (MFM). MFMs detect the Meissner effect, which is the repulsive force between a superconductor and a magnet, and Pasupathy’s lab can sense superconductors through covering layers at extremely cold temperatures.

Keren and Webb masterfully executed the MFM experiments, the results of which Rubio thought too good to be true. “Vacuum fluctuations are extremely small, but the effect observed is huge,” he said. Superconductivity was suppressed in the κ-ET to almost ½ micrometer—10x the width of the hBN flake used.

Modifying a material's properties in the past usually involved a shake of some sort, explained Rubio: a mechanical push, some added heat, or a laser pulse, to a short-lived effect. But without the external force, the modifications could be more persistent.  He and his fellow theorists on the paper are still working to reconcile a single explanation for the outstanding results. “Even if the theory doesn’t fully explain the results yet, we now have experimental proof of vacuum-mediated interactions in a material system. Long-term, this should be a major milestone,” said Rubio.

hBN’s hyperbolic nature is an important feature. Hyperbolic materials are uniquely structured in a way that enhances any internal vibrations—imagine the “wave” growing from a single person to an entire stadium. “It’s a remarkable effect that you can have with hyperbolic materials,” said Webb, now an assistant professor at Barnard College. “We now have a proof of concept that this is a viable way to modify the electronic properties of materials, and it’s something we could integrate into material designs.”

The vibrations in hBN can be tweaked, for one example, by changing its thickness. “If we can control these, we can tune our superconductor at will. But we aren’t just talking about superconductors,” said Keren. Different kinds of magnets and ferroelectric materials have specific vibrations associated with these properties; finding a matching cavity could be all it takes to modify them. “We expect to see others hunting for new combinations,” said Keren.