quanshengwu / wannier_tools

WannierTools: An open-source software package for novel topological materials. Full documentation:
http://www.wanniertools.org
GNU General Public License v3.0
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Example given for Chern number calculation #64

Open skdavidphy opened 4 years ago

skdavidphy commented 4 years ago

Dear Developers, Hope All are doing great jobs. wannier_tools is a nice package to carry out calculations regaridng topological properties. Unfortunately, I faced an conceptual question while following the Chern number calculation in the flllowing link http://www.wanniertools.com/images/wanniertools-FeSi-phonon.png

I think, here Chern number is calculated considering a spherical ball around the Weyl node for a particular band and observe the evolution of WCC as a function of azimuthal angle. I am not sure but if that is the case then the Chern number for band number 22,23 and 24 should be 2,2,0 respectively in the above given link. Please correct me if I am wrong. Why one should take the differences of those number of WCC evolutions for consecutive bands ? What Q(1-22) / Q(1-23) etc signifies ? However, T. Zhang in Ref. PRL 120, 016401 (2018) (supplement) didn't arrive at kind of WCC evolution for band no. 22,23, & 24.

I will be extremely grateful to you if you can explain those stuffs and help me to clear out my confusions.

Thank You. with regards, David