Reg. Conductance in Tutorial

[Rajib]

Dear ATK wizards,

A quick question regarding custom analyzer graph in the tutorial:

http://www.quantumwise.com/documents/tutorials/latest/GrapheneExplorer/index.html/chap.twister.html#sect1.twister.conductance

Does the graph shows the Conductance (G) or the conductance quantum G_0.

Please have look.

Rajib
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See attachment

[zh]

Yes, the right top panel shows the conductance of a ribbon as a function of the twisted angle.

[Anders Blom]

What it means is the "conductance in units of G0". May be confusing in this particular case, but consider other plots with "Energy (eV)" and it becomes clearer.

[Rajib]

Dear Dr. Anders Blom,

Many thanks.

I would very greatful, if you would please let me know about possible physical explanation of the decrease in conductance with increase in twist.

Rajib

[Anders Blom]

Without having done a careful analysis (that's your job, ours is to provide the software ), I'd say that the more you twist the ribbon the "less perfect" it is, and hence conducts worse. However, the really interesting part is perhaps not that it decreases, but the fact that it doesn't decrease very much, even if we twist it rather violently!

[nori]

I agree with Anders's consideration and let me make a supplementary statement.
Twisting nano-ribbon breaks the periodicity of the electronic structure, that leads to the collapse of ballistic transport.
But its influence against transport is relatively small, that means twisting does not affect drastically the sp2 bonding nature of Carbon.