Messages

1

General Questions and Answers / Re: Bloch State

« on: June 26, 2013, 14:51 »

A very thanks for your reply. The thing that I have not understood is:
How you read these Bloch states plots. I have read Wikipedia. But my question is, what can you predict from these plots. What do the red dots represent? What do the green region represent?
How the plots change by increasing K.

2

General Questions and Answers / Re: Transmission Spectrum

« on: June 26, 2013, 08:00 »

A very thanks for your reply. I am still not clear that you have written that at T=0, the conductance in units of G0 is given by the transmission coefficient at the Fermi level.  But I have calculated all the results at NO BIAS, i.e. I have not applied any voltage, so does it mean the same (i.e at T=0).
And without applying any voltage, how we get a transmission curve, as electron can only move from left to right in the presence of voltage.
And why we take transmission coefficient at the Fermi level.

3

General Questions and Answers / Bloch State

« on: June 25, 2013, 11:21 »

HI,
I know that according to Bloch Function, an electron in periodic potential has two parts in its wavefunction. One is the free particle wave function and the another term is the potential due to periodicity.
But I calculated the Bloch state of a Nanoribbon, for bloch index=16, and for k=0, 0.35, 0.5. I am also attaching the screenshot for the same, but I did not understand the result, why it is so.
Please explain me how to read these bloch states and why the plots are like this. Also, if I read the quantum wise ATK VNL manual, it is only given that the top one is conduction band and the bottom one is valance band.

4

General Questions and Answers / Transmission Spectrum

« on: June 21, 2013, 10:57 »

Hi,
Can anyone please explain me what is the formula by which transmission spectrum is converted to conductance at zero bias. I have searched it on internet, but I could not found it. I found the conductance using Transmission spectrum from analyzer, and I got two conductance, one G0 which is a straight line and one at the bottom, which is an integer value.
Please explain me for the same. I have also attached the TS curve with this query.

5

General Questions and Answers / Re: Conductance

« on: June 20, 2013, 11:24 »

can any one explain me how is it possible to get conductance without the application of Voltage and what is the difference between G and G0.

6

General Questions and Answers / Re: Transmission spectrum and conductance

« on: June 20, 2013, 11:01 »

 A very thanks for your reply sir. But I am sorry to say that I have still not understood that without applying any bias, how can an electron move from one part of the ribbon to another. For that we should apply some voltage, isn't it?
Also, when we do not apply apply, as in my case, i.e. to find the transmission spectrum of a GNR without the application of any voltage/current, do we call it a ZERO BIAS CONDITION, because in my opinion zero bias is a case when we apply 0 voltage, and in this case we are not applying any voltage.

Please reply.

7

General Questions and Answers / Transmission spectrum and conductance

« on: June 20, 2013, 07:08 »

Hi, I have calculated the Transmission spectrum for Graphene nanoribbon, and also calculated its conductance from analyzer.  I would like to know, what is the relation between conductance and transmission spectrum.
Also I would like to know I have calculated the transmission spectrum without the application of voltage and current. So, how is it possible that I get T(E) V/S E(eV) plot without the application of voltage and current.

Please revert.