AnswerBun.com

What measured quantity can be associated to the value of the J parameter in the Heisenberg/Ising hamiltonians?

Matter Modeling Asked on November 15, 2021

This question is related to other one here in the MatterModelingSE:

Here J is the exchange interaction parameters between two nearest-neighbor spins using in Heisenberg and Ising hamiltonians to study magnetic systems:

begin{equation}
tag{Heisenberg}
hat{H}_H=-sum_{langle i jrangle}Jhat{S}_ihat{S}_j
end{equation}

begin{equation}
tag{Ising}
hat{H}_I=-sum_{langle ijrangle}Jhat{S}_i^zhat{S}_j^z
end{equation}

Is there an experimental (and measurable) observable that can be related to the J parameter?

One Answer

Here I'll assume that the material is already believed to be roughly described by a model of the Heisenberg or Ising form. In that case, you just want a quantity that is easy to measure in your experiment and easy to extract from numerics (or with a well-established theoretical value).

In practice, the choice of which quantity to use will depend on convenience. If you are already set up to measure the temperature dependence of specific heat, you might do that. You might also measure $T_c$, or the magnetic field required to achieve total saturation. The choice will also be influenced by the parameter regime (temperature, field, pressure) in which the comparison to the theoretical model is the most relevant.

Here are a couple examples:

Answered by taciteloquence on November 15, 2021

Add your own answers!

Related Questions

Quantum Dot properties using VASP

2  Asked on August 19, 2021 by suseel-rahul

     

How to set vacuum space for slabs?

1  Asked on December 25, 2020 by barix

   

Ask a Question

Get help from others!

© 2022 AnswerBun.com. All rights reserved. Sites we Love: PCI Database, MenuIva, UKBizDB, Menu Kuliner, Sharing RPP, SolveDir