Prior thoughts on the Critical Magnetic Field. It is the nature of superconductors to exclude magnetic fields (Meissner effect - When a material makes the transition from the normal to superconducting state, it actively excludes magnetic fields from its interior) so long as the applied field does not exceed their critical magnetic field. This critical magnetic field is tabulated for 0K and decreases from that magnitude with increasing temperature, reaching zero at the critical temperature for superconductivity. The critical magnetic field at any temperature below the critical temperature is given by the relationship (via GSU)
Magnetism is a fundamental part of physics closely related to electricity. However, unlike electricity, it is impossible to isolate one of the poles and there has been no way of transmitting magnetism like wires can transmit electricity. This may all change due to researchers from Spain and Germany, whom have used a “hose” to transmit a magnetic field. The researchers successfully transmitted the field 4 centimeters but according to their work; they say it should theoretically work at much larger distances.
To accomplish this task, the team used a superconducting material, which encloses a ferromagnetic core. Rings of the ferromagnetic material enclosed by the superconducting surface were built concentrically upon one another to improve the performance. The researchers calculated that only two of these layers would be capable of transmitting 75% of the magnetic field, while 20 layers of the materials would be capable of transmitting 90% of the magnetic field. Additionally, the researchers also stated that such a cylinder could be manipulated to work within closed circuits.
A pioneer of transformation optics, John Pendry from Imperial College in London, explained, “It’s a rather novel idea. A superconductor expels all magnetic fields and can therefore be regarded as a perfect magnetic insulator, keeping the fields bottled up and preventing them from spilling all over the place.”
The work done by the researchers is very important to people who may be trying to further quantum computing. The researchers suggest the hoses can be used as a new way to address qubits inside quantum computers. Using magnetic hoses, spins of small crystals can be manipulated on the nano-scale. Likewise, Tie Jun Chi, an electrical engineer from Southeast University in China, mentioned, “Rather than electric circuits, this proposal would give us magnetic circuits.” The theoretical physicists created and tested this experiment themselves using instrumentation equipment that was readily available. With more research and better equipment, the scientist could possibly create a new method for controlling magnetism that could advance our magnetic technology greatly.
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