How do we add atomic number detail?
Dear All, I have never performed the conductance calculations earlier, and have just read the Kwant manual. I quite understood the defining of left,right leads and the scattering region. But I could not find anywhere how to add the atomic number details of the atoms used in leads, and the scattering region. Could somebody help me in this? The conductivity would depend on the lattice type, atom type etc. right? Regards,
Hi, Kwant is kind of general in terms of the type of tight-binding models it can simulate. On one hand you can start from a discrete model in terms of atoms and orbitals, but you can also take a continuous model and get a tight-binding model by discretizing it (see here http://kwant-project.org/doc/1.0/tutorial/tutorial1.html). The sites in a Kwant system are therefore not necessarily atoms; they could represent discretization points. Out of the box Kwant does not contain any physical "models", concretely this means that you have to provide all of the onsites/hoppings yourself depending on what model you want to simulate; this includes deciding on what your tight-binding model physically "means" (discretization of a continuous model vs. atoms/atomic orbitals). Hope that clarifies, Joe On 13 September 2015 at 20:10, siddheshwar chopra <sidhusai@gmail.com> wrote:
Dear All, I have never performed the conductance calculations earlier, and have just read the Kwant manual. I quite understood the defining of left,right leads and the scattering region. But I could not find anywhere how to add the atomic number details of the atoms used in leads, and the scattering region. Could somebody help me in this? The conductivity would depend on the lattice type, atom type etc. right?
Regards,
Dear Sir, Then how does the conductance graph differ between two honeycomb lattices..say for boron nitride nanoribbons and graphene nanoribbons? If it is atom independent then how does the I-V curve vary? Regards, On Mon, Sep 14, 2015 at 4:44 AM, Joseph Weston <joseph.weston08@gmail.com> wrote:
Hi,
Kwant is kind of general in terms of the type of tight-binding models it can simulate. On one hand you can start from a discrete model in terms of atoms and orbitals, but you can also take a continuous model and get a tight-binding model by discretizing it (see here http://kwant-project.org/doc/1.0/tutorial/tutorial1.html).
The sites in a Kwant system are therefore not necessarily atoms; they could represent discretization points. Out of the box Kwant does not contain any physical "models", concretely this means that you have to provide all of the onsites/hoppings yourself depending on what model you want to simulate; this includes deciding on what your tight-binding model physically "means" (discretization of a continuous model vs. atoms/atomic orbitals).
Hope that clarifies,
Joe
On 13 September 2015 at 20:10, siddheshwar chopra <sidhusai@gmail.com> wrote:
Dear All, I have never performed the conductance calculations earlier, and have just read the Kwant manual. I quite understood the defining of left,right leads and the scattering region. But I could not find anywhere how to add the atomic number details of the atoms used in leads, and the scattering region. Could somebody help me in this? The conductivity would depend on the lattice type, atom type etc. right?
Regards,
-- *Dr. Siddheshwar chopra,* *M.Sc., Ph.D (Physics)Assistant Professor (Physics),* *Amity University, Noida, India.*
Hi,
Dear Sir, Then how does the conductance graph differ between two honeycomb lattices..say for boron nitride nanoribbons and graphene nanoribbons? If it is atom independent then how does the I-V curve vary?
I do not believe I said anywhere that the conductance of a graphene nanoribbon and a Boron Nitride nanoribbon would be the same. What I said is that it is up to you, the user, to define *how* those two systems are different by supplying the onsites/hoppings that correspond to your physical model. For you Boron Nitride example I guess that this would mean (at the very least) giving different onsite values to the sites that correspond to Boron and Nitrogen atoms. The numerical values that you actually assign (and whether a simple single-orbital model is even valid) will depend on what physical model you are using; Kwant does not come with any such models out of the box. Hope that clarifies, Joe
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