superfluid helium tagged posts

Researchers at UBC have found a way to mimic the elusive Schwinger effect using superfluid helium, where vortex pairs appear out of thin films instead of electron-positron pairs in a vacuum. Their work not only offers a cosmic laboratory for otherwise unreachable phenomena, but also changes the way scientists understand vortices, superfluids, and even quantum tunneling.

In 1951, physicist Julian Schwinger theorized that by applying a uniform electrical field to a vacuum, electron-positron pairs would be spontaneously created out of nothing, through a phenomenon called quantum tunneling.

The problem with turning the matter-out-of-nowhere theory into Star Trek replicators or transporters? Enormously high electric fields would be re...

A half-quantum vortex combines circular spin flow and circular mass flow, leading to the formation of vortex pairs that can be observed experimentally. Image: Ella Maru Studio.

Gained understanding in quantum physics may be a step towards quantum computers. Researchers in Aalto University, Finland, and P.L. Kapitza Institute in Moscow have discovered half-quantum vortices in superfluid helium. This vortex is a topological defect, exhibited in superfluids and superconductors, which carries a fixed amount of circulating current. ‘This discovery of half-quantum vortices culminates a long search for these objects originally predicted to exist in superfluid helium in 1976,’ says Samuli Autti, Doctoral Candidate at Aalto University in Finland.

‘In the future, our discovery will provide access to...