Not a hole that worms live in, but the kind that spaceships use to bounce around the galaxy. Science Daily explains how Spanish scientists have created a wormhole in the lab:
Scientists in the Department of Physics at the Universitat Autònoma de Barcelona have designed and created in the laboratory the first experimental ‘wormhole’ that can connect two regions of space magnetically. This consists of a tunnel that transfers the magnetic field from one point to the other while keeping it undetectable — invisible — all the way.
The researchers used metamaterials and metasurfaces to build the tunnel experimentally, so that the magnetic field from a source, such as a magnet or a an electromagnet, appears at the other end of the ‘wormhole’ as an isolated magnetic monopole. This result is strange enough in itself, as magnetic monopoles — magnets with only one pole, whether north or south — do not exist in nature. The overall effect is that of a magnetic field that appears to travel from one point to another through a dimension that lies outside the conventional three dimensions.
The ‘wormhole’ in this experiment is a sphere made of different layers: an external layer with a ferromagnetic surface, a second inner layer, made of superconducting material, and a ferromagnetic sheet rolled into a cylinder that crosses the sphere from one end to the other. The sphere is made in such a way as to be magnetically undetectable — invisible, in magnetic field terms — from the exterior.
The magnetic wormhole is an analogy of gravitational ones, as it “changes the topology of space, as if the inner region has been magnetically erased from space,” explains Àlvar Sánchez, the lead researcher.
I’m not sure I understand how “magnetic invisibility” equals “erased from space,” but I’ll go with this one.