Cosmic physics mimicked on table-top as graphene enables Schwinger effect

The Schwinger effect is an elusive process that occurs only in Cosmic events. The team at the National Graphene Institute was able to produce particle-antiparticle pairs from a vacuum by applying high currents through specially designed devices.

A vacuum is thought to be completely empty. 70 years ago, it was predicted that electric or magnetic fields can break down the vacuum and create particles.

This requires fields around magnets or created during high-energy collisions of charged nuclei. Particle physics has a long-standing goal of probing theoretical predictions in a way that can be done with high-energy colliders around the world.

The research team, led by Prof Sir Andre Geim, has used Graphene to mimic the Schwinger production of electron and positron pairs.

The researchers were able to achieve strong electric fields in a simple, table-top setup with specially designed devices made from Graphene. Spontaneous production of electron and hole pairs was clearly observed and the process was well thought out.

The scientists observed another high-energy process that has no similarities to particle physics or astrophysics. They filled their vacuum with electrons and accelerated them to the maximum speed of light, which is 1/300 of the speed of light. At this point, electrons seemed to become superluminous, providing an electric current higher than allowed by general rules of quantum condensed matter physics. The origin of the effect was explained as the generation of additional charge carriers. The theoretical description of this process provided by the research team is different from the one provided by Schwinger.

People usually study the electronic properties using tiny electric fields. The paper's first author said that they decided to push the strength of electric fields as much as possible using different experimental tricks.

We wondered what could happen at this extreme. It was the Schwinger effect, not smoke coming out of our set-up.

When we first saw the spectacular characteristics of our superlattice devices, we thought it could be some sort of new superconductivity. The puzzling behavior was not superconductivity, but something in the domain of astrophysics and particle physics. It is curious to see such similarities.

The research is important for the development of future electronic devices based on two-dimensional quantum materials and establishes limits on wiring made from graphene that was already known for its remarkable ability to sustain ultra-high electric currents.

More information: Alexey I. Berdyugin et al, Out-of-equilibrium criticalities in graphene superlattices, Science (2022). DOI: 10.1126/science.abi8627. www.science.org/doi/10.1126/science.abi8627 Journal information: Science Citation: Cosmic physics mimicked on table-top as graphene enables Schwinger effect (2022, January 27) retrieved 27 January 2022 from https://phys.org/news/2022-01-cosmic-physics-mimicked-table-top-graphene.html This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.