Running Easyspin with a user-defined Hamiltonian

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christiansen
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Joined: Thu Apr 08, 2021 7:38 am

Running Easyspin with a user-defined Hamiltonian

Post by christiansen »

Dear Easyspin community

As the title says: Is it possible to run Easyspin with a user-defined function to set up the Hamiltonian instead of "sham/ham"? I want to simulate spectra of systems governed by double exchange interactions, which are not currently implemented in Easyspin.

Best,
Rasmus

Stefan Stoll
EasySpin Creator
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Joined: Mon Jul 21, 2014 10:11 pm
Location: University of Washington

Re: Running Easyspin with a user-defined Hamiltonian

Post by Stefan Stoll »

It is currently not possible to do this.

What specific form does the Hamiltonian have that you would like to add? Is it formulated in terms of spin operators?

Maybe this can be added to EasySpin.

christiansen
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Posts: 21
Joined: Thu Apr 08, 2021 7:38 am

Re: Running Easyspin with a user-defined Hamiltonian

Post by christiansen »

Hi Stefan

We actually discussed this on one of the ES zoom calls a while ago.

The Hamiltonian in question uses a different basis than the typical uncoupled m_J basis (new interaction, more quantum numbers needed). My guess is that one would need to define new transition operators in this basis. Could certainly be doable. The theory and expanded basis I am using is described in this paper: https://pubs.aip.org/aip/jcp/article-ab ... clusters-A. In their notation, I use the |Dm> representation

Cheers,
Rasmus

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