Physics: A magnetic wormhole

A spherical wormhole capable of transporting a magnetic field from one point to another along a path that is magnetically undetectable is demonstrated in Scientific Reports this week.

Wormholes are hypothetical passages capable of connecting two distant regions of space-time. A theoretical design to create a wormhole for electromagnetic waves has previously been proposed, in which electromagnetic waves propagate as if appearing in 3D-space with an invisible tunnel connecting the two points.

Inspired by this model, Alvaro Sanchez and colleagues used magnetic metamaterials and metasurfaces (materials and surfaces engineered to have properties not found in nature) to construct a spherical wormhole for a magnetic field. The authors demonstrate that a magnetic field from a source at one end entering the wormhole appears at the other end as an isolated magnetic monopolar-like field, creating the illusion of a magnetic field coming out of nowhere. The authors propose that their wormhole allows the passage of magnetic field lines through its interior while being magnetically invisible. The authors suggest that their work could have potential applications in medical techniques involving magnetism, such as magnetic resonance imaging (MRI).