QuantumATK Forum

QuantumATK => General Questions and Answers => Topic started by: hellboy on May 19, 2015, 06:25

Title: methods used for spin transport measurements
Post by: hellboy on May 19, 2015, 06:25

What method (or methods) is used to perform spin transport in MTJs, particularly interested in knowing

(i) coherent transport models for the spin transport
(ii) and the use of full-wave numerical simulation in spin transport.
(iii) how the doping is taken into account in  modeling spin transport (i.e., coherent transport in presence of doping in graphene)

Thanks in advance.

Title: Re: methods used for spin transport measurements
Post by: hellboy on May 20, 2015, 17:23

Any suggestions ?

Title: Re: methods used for spin transport measurements
Post by: Jess Wellendorff on May 20, 2015, 18:50

The theoretical foundation of DFT electron transport calculations using ATK  is pretty well covered in a scientific paper (http://journals.aps.org/prb/abstract/10.1103/PhysRevB.65.165401) as well as the ATK reference manual (http://www.quantumwise.com/documents/manuals/latest/ReferenceManual/index.html/chap.negf.html).

We use the non-equilibrium Greens function method, also for the case of spin transport. Several examples of this are available of tutorials on spintronics calculations, including MTJs (http://quantumwise.com/publications/tutorials/itemlist/category/95-spintronics).

Doping is easily handled by adding or removing background charge. This modifies the external potential acting on the Kohn-Sham one-electron states. See "http://quantumwise.com/publications/tutorials/item/820-ni-silicide-si-interfaces" and "http://quantumwise.com/documents/manuals/latest/ReferenceManual/index.html/ref.atomiccompensationcharge.html" for more info.

Hope this helps.

- Jess