Physicists have long wondered whether matter can spontaneously emerge from nothing, a process known as the Schwinger effect. Though the original idea required impossibly high electric fields, researchers at the University of British Columbia have now proposed a striking analog: using superfluid helium films to generate vortex pairs from a flowing “frictionless vacuum.” Credit: SciTechDaily.com
Superfluid helium reveals a manageable analog to the Schwinger effect. It deepens understanding of vortices and quantum tunneling.
In 1951, physicist Julian Schwinger proposed that applying a constant electric field to a vacuum could cause electron-positron pairs to emerge spontaneously, a process known as quantum tunneling.
Why can’t this matter from nothing idea power Star Trek replicators or transporters? The electric fields required would be extraordinarily large, well beyond the reach of any direct laboratory experiment.
Because of this limitation, the phenomenon, known as the Schwinger effect, has never been directly observed.
Superfluid helium as an experimental analog
Physicists at the University of British Columbia (UBC) have now outlined a related effect in a system that is easier to study. In their approach, a thin layer of superfluid helium replaces the vacuum, while the flowing motion of the superfluid takes the role of the immense electric field.
“Superfluid Helium-4 is a wonder. At a few atomic layers thick, it can be cooled very easily to a temperature where it’s basically in a frictionless vacuum state,” explains Dr. Philip Stamp, a theorist at UBC working on condensed matter and quantum gravity, whose new findings appeared in PNAS on 1 September 2025.
“When we make that frictionless vacuum flow, instead of electron-positron pairs appearing, vortex/anti-vortex pairs will appear spontaneously, spinning in opposite directions to one another.”
Mapping out the theory and experiments
In the paper, Dr. Stamp and UBC colleague Michael Desrochers outline the theory and the mathematics behind it—mapping out a detailed approach to conducting a direct experiment.
Vacuum tunneling is a process of keen interest in quantum mechanics and quantum field theory. In quantum theory, vacuums aren’t empty, they’re filled with fluctuating fields that can lead to the temporary appearance and disappearance of virtual particles.
“We believe the Helium-4 film provides a nice analog to several cosmic phenomena,” adds Dr. Stamp. “The vacuum in deep space, quantum black holes, even the very beginning of the Universe itself. And these are phenomena we can’t ever approach in any direct experimental way.”
Beyond analogs and into superfluid physics
However, Dr. Stamp emphasizes that the real interest of the work may lie less in an analogs – which always have limitations – and more in the way it alters our understanding of superfluids, and of phase transitions in two-dimensional systems.
“These are real physical systems in their own right, not analogs. And we can do experiments on these.”
At the mathematical level, the researchers needed several breakthroughs to make the theory work. For example, previous researchers looking at vortices in superfluids have treated the vortex mass as an unchanging constant. Dr. Stamp and Desrochers showed that this mass will vary dramatically as the vortices move, fundamentally changing our understanding of vortices in both fluids and the early universe.
“It’s exciting to understand how and why the mass varies, and how this affects our understanding of quantum tunnelling processes, which are ubiquitous in physics, chemistry, and biology,” says Desrochers.
Stamp also argues that the same mass variability will occur with electron-positron pairs in the Schwinger effect, thereby modifying Schwinger’s theory, in a kind of ‘revenge of the analog’.
Reference: “Vacuum tunneling of vortices in two-dimensional 4He superfluid films” by M. J. Desrochers, D. J. J. Marchand and P. C. E. Stamp, 2 September 2025, Proceedings of the National Academy of Sciences.
DOI: 10.1073/pnas.2421273122
The work was supported by the National Science and Engineering Research Council.
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