A team from Canada and Japan has achieved a groundbreaking feat: observing superfluidity in molecular hydrogen for the first time. This phenomenon, previously seen only in helium, involves a substance flowing without resistance, as if its particles do not interact.
Superfluidity occurs when certain fluids approach absolute zero, undergoing a phase transition to a state of zero viscosity, fundamentally altering their behavior. "This discovery deepens our understanding of quantum fluids and may inspire more efficient ways to store and transport hydrogen for clean energy," stated Professor Takamasa Momose from the University of British Columbia.
To overcome the challenge of hydrogen solidifying at -259 °C, far above absolute zero (-273.15 °C), the team confined small clusters of hydrogen molecules within helium nanodroplets, reaching -272.25 °C. They then introduced a methane molecule into the hydrogen cluster and rotated it using laser pulses.
The rotating methane molecule served as an indicator: its frictionless rotation signaled the surrounding hydrogen's superfluid behavior. Indeed, with 15 to 20 hydrogen molecules in the cluster, the methane rotated without resistance, confirming the superfluid state.
While a direct application isn't immediate, the frictionless flow of superfluid hydrogen could inspire new technologies for hydrogen transport and storage, crucial for advancing clean energy solutions. Hydrogen, used in fuel cells that emit only water, faces infrastructure challenges in production, storage, and transport. This discovery may pave the way for practical clean fuel options.