Scientists strengthen superconductor using quantum vacuum fluctuations

October 3, 2026 at 05:24 PM2 min

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Researchers at the University of Science and Technology of China demonstrated that quantum vacuum fluctuations can strengthen superconductivity in NbSe2. The team placed the superconductor inside a terahertz dark cavity and observed a significant increase in its critical temperature. The study, published in Nature, opens a new path for controlling unusual states of matter.

Key Facts

The study was published in Nature and led by Profs. Changgan Zeng and Guanghui Cheng of the University of Science and Technology of China.
The collaboration included Prof. Qingdong Jiang of Shanghai Jiao Tong University and Prof. Frank Wilczek of the Massachusetts Institute of Technology.
The researchers introduced the concept of 'vacuumronics' to describe engineered vacuum environments controlling electronic and photonic behavior.
The experiment used a terahertz split-ring resonator, described as a 'dark cavity', to amplify vacuum fluctuations.
Placing NbSe2 inside the cavity significantly increased its superconducting critical temperature.

Quantum Vacuum Fluctuations

According to quantum electrodynamics and the Heisenberg uncertainty principle, even the lowest energy state is never perfectly still. Virtual particles continually appear and disappear, producing an ever-present background of quantum fluctuations. These fluctuations have been observed through phenomena such as the Lamb shift, spontaneous emission, and the Casimir effect. In an earlier study, the researchers showed they could directly manipulate vacuum fluctuations by using a magnetic field to reversibly switch the Casimir force between attraction and repulsion.

Experimental Demonstration

To overcome the weakness of free-space vacuum fluctuations, the team introduced a terahertz split-ring resonator, a 'dark cavity' that reshapes the electromagnetic environment and substantially amplifies vacuum fluctuations. The researchers placed the superconductor NbSe2 inside the terahertz dark cavity, creating a coupled system with the engineered electromagnetic environment. They compared the material's superconducting behavior inside and outside the cavity. The results showed that placing NbSe2 in the cavity significantly increased its superconducting critical temperature.

Theoretical Framework

Prof. Qingdong Jiang's group at Shanghai Jiao Tong University studied how engineered quantum vacuum environments could influence different states of matter from a theoretical perspective. They introduced the concept of 'vacuumronics', in which specially designed vacuum environments are used to control electronic and photonic behavior. This theoretical work provided a framework for understanding the superconductivity enhancement observed in the new experiments.