Shahar Simon, a Ph.D. student in Jerusalem, was listening to atoms sing. What he heard sounded like one voice—but it was actually two, perfectly in sync. Simon and his team at Hebrew University have just discovered that two well-studied atom-thin materials don't behave the way scientists thought. The finding could one day help build better quantum computers, faster electronics, and smarter sensors.
The materials are called niobium diselenide (NbSe₂) and tantalum disulfide (TaS₂). Both are superconductors—special materials that can carry electricity with almost zero energy loss. When scientists peel these materials down to just a few layers of atoms thick, they appear to behave simply, with one clear superconducting "fingerprint."
But Simon, working alongside M.Sc. student Maya Klang under Professors Oded Millo and Hadar Steinberg, found something hidden. Using a technique called tunneling spectroscopy—which measures how electrons move between tiny surfaces—the team discovered these materials actually contain not one but two superconducting states working together. They disguise themselves as a single state, which is why no one noticed before.
"It's a bit like listening to what sounds like a single singer, only to discover it's actually a perfectly synchronized duet," the researchers said.
The discovery solves a puzzle that has puzzled physicists for years. Earlier experiments couldn't fully explain how these materials behave using simple models. But by accounting for two interacting superconducting orders, the team could suddenly explain their measurements—plus how the materials respond when exposed to magnetic fields. Even more surprising: the thicker, bulk version of NbSe₂ may actually contain three such orders, not just two.
The team published their results in Physical Review Letters, a top physics journal. And the implications stretch far beyond the lab. Quantum computers, which could solve problems too hard for regular computers, rely on materials like these. So do advanced sensors used in medicine and security. Understanding exactly how electrons pair up and flow without resistance inside these materials could help engineers design more reliable devices.
"Sometimes the biggest discoveries come from looking more closely at something we thought we already understood," the researchers noted. For Simon, Klang, and their colleagues, that closer look just revealed a richer, more surprising universe hiding inside ordinary matter.