Hi, It is correct that for V=0 and dT=0 there is no current.
The *bond currents*, or lets call them orbital currents, can be viewed as how the electrons would pass through the structure at a given k-point and at a specific energy. So if you consider an infinitesimal V the bond-current at E=Ef would be how the electrons pass through the device. One can then calculate how the full current passes through the device by integrating the bond-currents (as one would do for the transmission) for the entire bias window. You should be able to cut the orbital-currents such that you find the total transmission. However, the cut must cut the full device in 2; but how you make that cut is up to you. So I don't know how you did it, but I think something went wrong then ;) As for getting the incoming and reflection waves. That is not as trivial and we have not tried to do it with the current quantities that can be calculated (I think you need one more term). But what you can do is calculate the reflected transmission. You calculate the bulk transmission and the total transmission. Subtract the two and you have the reflected transmission. Den lør. 30. okt. 2021 kl. 22.00 skrev zhyphy <zh...@mails.jlu.edu.cn>: > Dear All， > I want to do some analysis of the relationship between structures and > currents. I can successfully extract data with SISL program.But I'm > confused about the physical sense of bond current. I noticed that, in some > literatures, they used equilibrium results to obtain bond-current at some > incident energy. But in equilibrium, isn't there no current through the > device? So what does this bond current stand for? > When the current is stable, the current flowing in and out of the cross > section at any position of the device should be equal.Therefore, the sum of > the bond-currents in any section should be equal. But my calculation is > not so.Is there something wrong with my understanding of bond current? > Due to the potential barrier between atoms, the wave function between > bonds should be the superposition of incident wave and reflected wave. Can > I extract the contribution of incoming and outgoing waves to the total > current respectively? > I really appreciate that someone can help me understand the sense of bond > current. > > best regards, > zhy > > > -- > SIESTA is supported by the Spanish Research Agency (AEI) and by the > European H2020 MaX Centre of Excellence (http://www.max-centre.eu/) > -- Kind regards Nick
-- SIESTA is supported by the Spanish Research Agency (AEI) and by the European H2020 MaX Centre of Excellence (http://www.max-centre.eu/)
