Numerical validation of quantum magnetic ordering

Oct 22, 2013

A new study set out to use numerical simulations to validate previous theoretical predictions describing materials exhibiting so-called antiferromagneting characteristics. A recently discovered theory shows that the ordering temperature depends on two factors-namely the spin-wave velocity and the staggered magnetisation. The results, largely consistent with these theoretical predictions, have now been published in a paper in the European Physical Journal B by Ming-Tso Kao and Fu-Jiun Jiang from the National Taiwan Normal University, in Taipei.

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 , 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.

They found that the universal relation is valid to a great extent, while there is a discrepancy between the and the simulation results. Further investigation, they believe, is required in order to better understand the discrepancy. For example, this could mean investigating whether the predicted universal relation is valid qualitatively or quantitatively for the same type and different type of quantum phase transitions occurring in other models than that considered here.

Explore further: Quantum computers could greatly accelerate machine learning

More information: M.-T. Kao, F.-J. Jiang (2013), Investigation of a universal behavior between Néel temperature and staggered magnetization density for a three-dimensional quantum antiferromagnet, European Physical Journal B, DOI: 10.1140/epjb/e2013-40726-6

Related Stories

Understanding a new kind of magnetism

Sep 23, 2013

Using low-frequency laser pulses, a team of researchers has carried out the first measurements that reveal the detailed characteristics of a unique kind of magnetism found in a mineral called herbertsmithite.

Recommended for you

Scientists succeed in linking two different quantum systems

Mar 30, 2015

Physicists at the Universities of Bonn and Cambridge have succeeded in linking two completely different quantum systems to one another. In doing so, they have taken an important step forward on the way to a quantum computer. ...

First glimpse inside a macroscopic quantum state

Mar 27, 2015

In a recent study published in Physical Review Letters, the research group led by ICREA Prof at ICFO Morgan Mitchell has detected, for the first time, entanglement among individual photon pairs in a beam ...

Theory of the strong interaction verified

Mar 26, 2015

The fact that the neutron is slightly more massive than the proton is the reason why atomic nuclei have exactly those properties that make our world and ultimately our existence possible. Eighty years after ...

3,000 atoms entangled with a single photon

Mar 25, 2015

Physicists from MIT and the University of Belgrade have developed a new technique that can successfully entangle 3,000 atoms using only a single photon. The results, published today in the journal Nature, repres ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.