Using metamaterials to transmit magnetic fields

MIT Technology Review : Metamaterials have already been used to guide and direct electromagnetic waves in unusual ways . Now Carles Navau of the Autonomous University of Barcelona and his colleagues have shown that a static magnetic field can be manipulated in a similar way. Their design consists of a 7-cm-long tube made of a series of concentric rings, which was filled with a ferromagnetic alloy. At one end of the tube they generated a 1.3-mT magnetic field. A crack farther down the tube allowed the magnetic field to escape. When they measured the field escaping, they found it to be 0.8 mT in strength. That was significantly greater than the field strength at that distance from the source without the tube. Navau suggests that the ability to project magnetic fields over longer distances might be useful in quantum computing, where they are needed for manipulating quantum bits.