Quantum Magnetism
Antiferromagnetic Order in Sr3Ru2O7
Dr Chris Lester and Professor Stephen Hayden of the Correlated Electrons Group at the University, together with collaborators, have found that a large magnetic field induces antiferromagnetism in Sr3Ru2O7. The results were published in Nature Materials.
They found that an 8 Tesla magnetic field induced a form of antiferromagnetism, known as a spin density wave, at temperatures less than 1 Kelvin. This solves a long standing mystery of the ordered state in Sr3Ru2O7. The state of the spin density wave can be controlled by rotating the sample with respect to the magnetic field. This leads to large changes in the resistance of the metal.
The results have analogies with molecular systems. Here phases with broken translation symmetry (such as liquid crystals, and ice) exist over a range of pressure (instead of field). This is bounded by isotropic phases of higher symmetry. It also suggests a new method to control the resistance of a metal in a high magnetic field
