From Singapore: The headline sounds like it belongs in a science fiction novel. Particles that do not exist are influencing the behaviour of a superconductor. Yet that is precisely what a new study published in Nature has demonstrated, and the implications for materials science, and eventually for industries that depend on superconducting technology, could prove significant over time.
The research centres on a concept from quantum field theory called virtual photons. In quantum mechanics, even empty space is threaded by fields that govern how particles interact. Photons, the particles of light, represent energetic excitations of the electromagnetic field. Virtual photons are a related phenomenon: they do not travel through space as detectable light does, but they mediate electromagnetic forces between particles and can accumulate in materials with strong, structured electromagnetic fields. You cannot catch one, but you can certainly observe what they do.
The experiment exploited a property of hexagonal boron nitride, a material that, like graphene, forms macroscopic sheets of interlocked hexagonal rings. Because of the precise atomic spacing within those sheets and the distance between layers, only certain wavelengths of light can travel smoothly through the material. Everything else is absorbed or scattered. This selectivity means that hexagonal boron nitride is, in effect, a reservoir of virtual photons at those specific wavelengths, even when no real photons are present at all. NASA has previously explored boron nitride for its radiation-shielding properties, but this new research reveals a far stranger capability.
The superconductor at the centre of the study is a copper-organic compound with a formidable name, abbreviated to κ-ET, which becomes superconducting at around 12 Kelvin. It is not an especially impressive superconductor by performance standards, but it operates through a mechanism that researchers do not fully understand. A carbon-carbon double bond within the compound is thought to play a role in the onset of superconductivity, and crucially, the frequency at which that bond vibrates corresponds to the infrared wavelengths that hexagonal boron nitride allows through. That coincidence gave the researchers a lever to pull.
By placing a layer of boron nitride on top of κ-ET and measuring how much force was required to bring a magnet close to the superconductor, the team found that the boron nitride reduced the material's ability to expel magnetic fields, a defining feature of superconductivity. Substituting other materials produced no such effect. A chemically related superconductor with a different bond structure was similarly unaffected. The interaction appeared to be specific: virtual photons at the boron nitride's characteristic wavelengths were coupling with the carbon-carbon bond vibrations and weakening the superconducting state.
The honest caveat is that this result moves in the wrong direction for practical applications. Boron nitride is suppressing superconductivity, not enhancing it. The researchers have not yet determined how deeply the suppression penetrates the material or whether it reduces the critical temperature. No one is suggesting this path leads to room-temperature superconductors.
The more interesting claim is methodological. Superconductivity research has long been constrained by two basic tools: temperature and pressure. Adjusting either can shift a material in and out of its superconducting state, but beyond that, the options narrow quickly to changing the material's chemistry outright. This experiment suggests a third avenue, using the electromagnetic environment created by a neighbouring material to probe and manipulate what is happening inside a superconductor, without touching the chemistry at all.
That matters because some of the most interesting superconductors require conditions that are economically impractical at scale. Understanding the mechanisms that drive superconductivity in these exotic compounds, even through indirect means like virtual photon coupling, is one of the few realistic paths toward eventually replicating those effects under more accessible conditions. Hexagonal boron nitride is just one such probe. Other layered materials with resonances at different wavelengths could, in principle, be used to interrogate different aspects of superconducting behaviour.
The full study is available via Nature, DOI: 10.1038/s41586-025-10062-6. For Australian researchers and technology investors, the broader lesson is that quantum materials science is generating new experimental vocabulary faster than applications can follow. That gap will not last indefinitely.