In antiferromagnetic materials, the spins of electrons align in a regular pattern pointing in opposite directions to their neighbours. The materials magnetic ordering conditions the temperature, referred to as the Néel temperature, above which the macroscopic magnetic ordering is no longer present. The authors attempted to confirm a new universal law established between the thermal and quantum properties of these three-dimensional quantum antiferromagnets. Specifically, the law suggests that the Néel temperature can be related to the staggered magnetisation density near a quantum critical point (QCP). At that point, there is a special class of continuous magnetic phase transition taking place at the absolute zero of temperature, driven by quantum-level fluctuations. In order to produce quantitative predictions, they simulated a specific three-dimensional relevant model using the first principles of approximation-free Monte Carlo calculations. The authors thus extracted the Néel temperature, the zero-temperature staggered magnetisation in the system and the spinwave velocity. phys.org/news/2013-10-numerical-validation-quantum-magnetic.html
Posted on: Thu, 24 Oct 2013 02:47:50 +0000