24
votes
Accepted
Calculating HSE06 band structures on Quantum ESPRESSO
I have seen all the methods you mentioned but have only done one myself; I'll explain here how to use Wannier90 in conjunction with Quantum Espresso to get band structures for hybrid functional ...
- 3,191
16
votes
Accepted
Berry's curvature and magnetic moment in TMDCs
The Berry curvature is defined as:
$$
\Omega_{\mu\nu}(\mathbf{k})=\partial_{\mu}A_{\nu}(\mathbf{k})-\partial_{\nu}A_{\mu}(\mathbf{k}),
\tag{1}
$$
where $A_{\mu}(\mathbf{k})=\langle u_{\mathbf{k}}|i\...
- 11.2k
12
votes
Berry's curvature and magnetic moment in TMDCs
Resolution for the time reversal symmetry:
I need to demonstrate: $\Omega(-\mathbf{k})=-\Omega(\mathbf{k})$ (Berry's curvature is a odd function under time reversal symmetry)
Berry's curvature:
$$\...
- 1,763
10
votes
Accepted
Anomalous Quantum Hall Effect
What is the quantum anomalous Hall effect?
Figure from C-X. Liu, S-C. Zhang, and X-L. Qi. "The Quantum Anomalous Hall
Effect: Theory and Experiment," Annual Review of Condensed Matter ...
- 4,761
9
votes
Calculating HSE06 band structures on Quantum ESPRESSO
Apart from methods (1) and (2) mentioned in the question, the third method I found to be pretty viable under certain conditions. The procedure involves mathematical interpolation of the bands, so I ...
- 2,506
9
votes
How does a beginner condensed matter theorist working on real materials, get up to speed?
Welcome to the club of academic migrants! I didn't take any university-level chemistry courses during my undergrad years (except a special topics course for graduate students called "...
9
votes
Accepted
Why can't we change the spin angular momentum of electrons with an external optical field?
This has already been asked in several forms in Physics Stack Exchange. Within the semi-classical 'electric dipole' approximation, only the electric field of light interacts with the electron. The ...
- 2,422
9
votes
Accepted
Physical origin for higher bandgaps when going from bulk to few-layers
Quantum confinement can occur when the exciton (electron-hole quasiparticle) radius is larger than the size of the semiconductor. Due to this confinement, the energy levels which can be occupied by ...
- 11.4k
8
votes
Accepted
Inversion symmetry in 2D materials
Let's give it another go: In the monolayer you would place the inversion centre on the green atom. But this would reverse the direction of the trigonal prism formed by the yellow atoms. Hence, there ...
- 1,431
7
votes
How does a beginner condensed matter theorist working on real materials, get up to speed?
I'm grad student about to finish their PhD, so you may find my perspective valuable.
For reference, my undergrad degree was in physics and math, where I did big data analysis on high energy data ...
- 683
7
votes
How to derive the effective Hamiltonian of two-dimensional TMDCs monolayers?
How do you get the Hamiltonian formula for transition metal dichalcogenides? How to derivate the expression above (equation (1))?
You can use the $ k \cdot p$ method to derive this effective ...
- 15.3k
7
votes
Accepted
Separation of valence bands in transition metal dichalcogenides (TMDs)
I should start by saying that I am no expert in MoS$_2$, so this answer is my guess from looking at the reference you provide, and would be happy if someone corrects me.
The general things to keep in ...
- 11.2k
6
votes
VASP Dielectric constants: What potential to use?
I don't think there is a consensus of norm conserving PP being more accurate. There are some references I am aware of which have calculated dielectric tensor using NC-PP, but without justification ...
- 1,257
6
votes
Accepted
Quantum confinement of transition metal dichalcogenides (TMDs)
Quantum confinement is a kind of physical effect, which describes the change of electronic and optical properties when the material sampled is of sufficiently small size----typically 10 nanometers or ...
- 15.3k
6
votes
Why can't we change the spin angular momentum of electrons with an external optical field?
well, you certainly can change the spin of an electron through acting on its orbital motion with the electric field. It is called "spin-orbit coupling" (SOC) and a lot of magneto-optical and ...
- 291
5
votes
Why can't we change the spin angular momentum of electrons with an external optical field?
I think the claim assumes linear polarization of the light which has zero angular momentum. For circularly polarized light, the spin of the electron should be flipped. (e.g. Appl. Phys. Lett. 114, ...
- 2,098
4
votes
How to derive the effective Hamiltonian of two-dimensional TMDCs monolayers?
As @Jack suggested, try the $\vec{k} \cdot \vec{p}$ method.
The hopping integral $t_{ij}$ is "borrowed" from the Hubbard model. It is the kinetic term in the Hamiltonian that explains ...
- 469
3
votes
Accepted
Modeling techniques for simulating the electronic and structural properties of Transition Metal Dichalcogenide nanotubes
I'd recommend ChiralTube: http://chiraltube.com
The code (and simulations) were covered in a recent publication:
"Chiraltube, rolling 2D materials into chiral nanotubes"
The code is also ...
- 9,375
3
votes
How does a beginner condensed matter theorist working on real materials, get up to speed?
Answering "How does a beginner condensed matter theorist working on real materials, get up to speed?" is not as easy as it could appear.
From my own experience, if you are a condensed matter ...
- 24k
3
votes
Valleys and time reversal symmetry (Zeeman effect)
First of all, H-phase TMDC monolayers like $\ce{WSe_2}$ are non-magnetic semiconducting materials, which means the time-reversal symmetry (TRS) is preserved. Therefore, you can say the energy states ...
- 15.3k
3
votes
Accepted
Best vdW correction functional for transition metal dichalcogenides
DFT-D2 is simple and reliable. I've used DFT-D2 for most of my worked on 2D materials but I do I have to caution you that I have not specifically work on TMGs. You can test out the results you obtain ...
- 2,422
2
votes
Separation of valence bands in transition metal dichalcogenides (TMDs)
ProfM's argument is absolutely right. Here I support a more detailed explanation based on first-principles calculations.
The spin-resolved band structure of monolayer MoS$_2$ with the consideration of ...
- 15.3k
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