Questions tagged [transport]
Questions related to transport phenomena (e.g. charge transfer, heat conduction, molecular diffusion).
39 questions
2 votes
1 answer
49 views
How to express velocity with non-orthogonal hamiltonian and overlap matrice?
Suppose H and S are Hamiltonian and overlap matrices for the system with non-orthogonal basis. I am trying to use Kubo-Greenwood formula, equation (1), to compute the conductance for the 2D materials. ...
- 1,103
0 votes
0 answers
34 views
There are problems when calculating the projected transmission rate using tbtrans
I am calculating a four-electrode single-molecule device based on a graphene-naphthalene molecule-graphene structure, which has a total of 338 atoms. I have already calculated the transmission rate. ...
- 21
0 votes
0 answers
24 views
I encountered the problem of band crossings when using TBTrans to calculate the projected transmission
I'm calculating a four-electrode single-molecule device based on a graphene-naphthalene molecule-graphene structure, which consists of a total of 338 atoms. I've already calculated the transmission ...
- 21
5 votes
0 answers
49 views
Fourier transform expression of the coulomb interaction between the sheets(graphene)
Do you know any expression which can present the Fourier form of coulomb interaction between two graphene sheets separated by vacuum (as the figure above)? Here S(w) is the transmission equation. ...
- 51
0 votes
1 answer
64 views
Number of orbitals per atom in the electrode does not match the system electrode
I had the following question during transiesta calculation. ...
- 287
1 vote
1 answer
110 views
how to model gate oxide in transiesta?
The gate oxide is located between the gate electrode and the channel of semiconductor material, acting as an insulating layer to prevent current from flowing directly from the gate into the ...
- 287
2 votes
1 answer
68 views
What would happen if I did not set up %block TBT.HS.Files correctly?
I have calculated the SCF solution of a certain system at 21 different applied bias from 0.0 to 2.0 at steps of 0.1 eV. However, when I set up block TBT.HS.Files, I ...
- 287
3 votes
0 answers
47 views
Difference in DOS and Transmission in the ballistic regime
Regarding the calculation of the transmission function, I understand that this is related to the number of modes * the transmission probability, and in the case of ballistic calculations the ...
- 1,643
0 votes
1 answer
84 views
What can we learn from the local device density of states?
Many papers on quantum transport show results on local device density of states. What can we learn by inspecting local device density of states?
- 287
4 votes
1 answer
170 views
Differences between Landauer formalism and Boltzman transport
I am trying to have an intuitive understanding of the differences between Boltzman transport and Landauer formalism. In particular, while it is clear that the first measures the conductivity, thus the ...
- 1,643
1 vote
1 answer
83 views
why does transiesta calculation time increase with the voltage during transport properties calculation?
In my research, I used semiconductors as channel materials and metals as electrodes to calculate the transport properties under different bias voltages. I found that the calculation time kept ...
- 287
2 votes
0 answers
58 views
Should we do convergence testing on energy points in the non-equilibrium contours?
I met the following warnings after Transiesta calculations. ...
- 287
2 votes
0 answers
66 views
Is it reasonable to extract the Schottky barrier height from the zero-bias transmission spectrum?
The following question is based on discussions What's meaning of zero energy reference point in the energy-axis of zero-bias transmission spectrum extracted by sisl.get_sile('systemlabel.TBT....
- 287
3 votes
2 answers
246 views
What is the difference between k-averaged transmission and gamma point transmission?
When I used Transiesta to calculate transmission, I found that k-averaged transmission is the same as gamma point transmission for some devices and they are different for other devices. What is the ...
- 287
2 votes
1 answer
119 views
Is it safe to delete self-energy files SystemLabel.TSGF* during transport properties calculations at different bias values?
Siesta stopped because of running out of disk space in my workstation during transport properties calculations at different bias values. I would like to calculate transport properties for bias values ...
- 287