QuantumATK Forum

QuantumATK => General Questions and Answers => Topic started by: Dipankar Saha on March 28, 2015, 21:28

Title: Fermi velocity
Post by: Dipankar Saha on March 28, 2015, 21:28

In ATK .......... how can we obtain Fermi velocity ?

Title: Re: Fermi velocity
Post by: zh on March 30, 2015, 11:27

For the calculation of the Fermi velocity of graphene at the Dirac point, you can refer to the following  paper:
http://arxiv.org/pdf/1302.1843v1.pdf

Title: Re: Fermi velocity
Post by: Umberto Martinez on March 30, 2015, 11:29

Let me add that it will be possible to perform this analysis "out of the box" with the next release, ATK 2015.

Title: Re: Fermi velocity
Post by: Dipankar Saha on April 1, 2015, 15:28

Thanks a lot zh for your reply..... :)   

Title: Re: Fermi velocity
Post by: Dipankar Saha on April 1, 2015, 15:29

Umberto Martinez,

That will be of great help ..... !!! Thank you .... :)

Title: Re: Fermi velocity
Post by: Dipankar Saha on April 21, 2015, 20:15

Dr. Umberto Martinez,

As it was said earlier,  ......we really do expect to see  the  analysis 'out of the box' __ featuring the calculation of "Fermi velocity"  (with your next  release)  !!!   :)

Thanks and Regards___
Dipankar

Title: Re: Fermi velocity
Post by: Dipankar Saha on September 3, 2015, 20:36

Hello,
Is this  feature available....in RC1 ?

Best_
Dipankar

Title: Re: Fermi velocity
Post by: Jess Wellendorff on September 4, 2015, 15:48

Yes, ATK 2015.rc1 calculates the Bloch-state velocity = 1/hbar dE/dk from first-order pertubation theory. Please see the attached script. The value v_F = 8*10^5 m/s matches literature values (~10^6 m/s) very well. There will probably not be VNL scripter support for this analysis.

Title: Re: Fermi velocity
Post by: Dipankar Saha on September 4, 2015, 17:47

Thanks a lot Jess.....!!!  :)
____________
By d way, is this method...named "calculateVelocity" is a generic one..... (for a given k-point  and the band. struct. ) ??

Title: Re: Fermi velocity
Post by: Jess Wellendorff on September 7, 2015, 13:35

The function works for a given k-point and for a given list of band indices.

Please note that the function resides in the more experimental part of the ATK code. This means it works, but does not necessarily provide useful error messages or checks on validity of the input parameters. For expert users only :) Also, we provide only limited support on such functionality.

Title: Re: Fermi velocity
Post by: Dipankar Saha on September 7, 2015, 17:09

Dr. Jess Wellendorff,

Many Thanks ......  :)