Superconductors can be used to make extra strong magnetic fields

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 The application of a sufficiently strong magnetic field to a superconductor will, in general, destroy the superconducting state. Two mechanisms are responsible for this. The first is the Zeeman effect1, 2, which breaks apart the paired electrons if they are in a spin-singlet (but not a spin-triplet) state. The second is the so-called ‘orbital’ effect, whereby the vortices penetrate into the superconductors and the energy gain due to the formation of the paired electrons is lost3. For the case of layered, two-dimensional superconductors, such as the high-Tc copper oxides, the orbital effect is reduced when the applied magnetic field is parallel to the conducting layers4. Here we report resistance and magnetic-torque experiments on single crystals of the quasi-two-dimensional organic conductor λ-(BETS)2FeCl4, where BETS is.

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