Questions tagged [solid-state-physics]
Questions about solid state physics.
33
questions
7
votes
1answer
45 views
How to numerically calculate quantum state distance using quantum metric?
In Ran Cheng's review of the quantum geometric tensor, eq. (11) gives the tensor as:
$$
Q_{\mu\nu}=\sum_{n\neq 0}\frac{\langle\phi_0|\partial_\mu H|\phi_n\rangle\langle\phi_n|\partial_\nu H|\phi_0\...
5
votes
0answers
39 views
Which software is suitable for visualizing the electron wavefunctions in a crystal?
I'd like to use the tight-binding model with a linear combination of atomic orbitals.
It should show the full energy bands, as well as the spatial probability distribution for each eigenfunction of ...
9
votes
1answer
404 views
Why is the planewave codes ecosystem healthier on free/opensource software adoption, when compared to codes supporting atom-centered orbitals?
Regarding the branch of matter modeling that deals with electronic structure methods, I think we can divide it in two camps: Those who work mostly with planewave-based software, geared towards ...
5
votes
0answers
38 views
Constructing the symmetry operator from k.p Hamiltonian
I have a question regarding to how to construct an operator from k.p Hamiltonian. Maybe there are some problems in my understanding, I hope you can point me out and correct my description if I made ...
8
votes
0answers
133 views
transition dipole matrix element
When doing DFT calculations of periodic solids, from either $\mathbf{k \cdot p}$ perturbation theory or simply using the trick $\mathbf{r} \rightarrow i\partial_{\mathbf{k}}$, one can obtain
$$
\...
6
votes
0answers
50 views
Constructing an anisotropic crystal in WulffPack
I am trying to create an LiFePO4 crystal in WulffPack. I have the surface energies of seven different surfaces from the paper [1]. When I input the same to WulffPack, it creates a structure comprising ...
12
votes
2answers
87 views
What are properties of interest for energy storage materials?
In the field of simulation for energy storage materials, there is always a gap between theoretical calculations and demand for experimentalists. What could be directly calculated from ab initio ...
17
votes
4answers
381 views
Good books about computational chemistry of solid state materials for newbie
At the University, I chose the organic chemistry path and to better understand my experimental works I started studying computational chemistry on my own. There are a lot of books in this field, but I ...
10
votes
1answer
305 views
Increasing k-point grid to take DOS calculation
I was trying to compute some electronic properties for Pd using SIESTA and VASP for some computer practicals in my university, specially focused on band structure and density of states (DOS) using LDA ...
8
votes
0answers
88 views
Example of a standard/archetypal/simple 4-band gapped condensed matter model with analytic results?
I am looking to study Berry phase-like phenomena in a gapped 4-band material model. In particular, I want to numerically and analytically calculate the Abelian Berry curvature integral of each band ...
6
votes
1answer
59 views
Example of a standard/archetypal/simple 4-band un-gapped condensed matter model with analytic results?
I am looking to study Berry phase-like phenomena in an un-gapped material model. However, I am having trouble finding a widely-used 4-band model with analytic expressions for wavefunctions and ...
9
votes
1answer
94 views
Can I have a bond formed for only one spin?
I'm making a topological analysis of a nanotube interacting with some metals.
The steps for the calculations were:
Optimizing the geometry (I am using SIESTA code).
Obtain the electronic density for ...
9
votes
0answers
52 views
Methods to determine the vacuum level in 2D compounds in the presence of dipoles
When 2D compounds have a dipole, the potential distribution becomes linear (the left panel of the figure). After considering the dipole correction, the potential has two plateau regions in the vacuum (...
5
votes
0answers
106 views
Why does numerical computation of Berry curvature give me a correct Berry phase when it is supposed to diverge?
I implemented the standard numerical algorithm for calculating the Berry curvature in MATLAB. For a given 2D system, I can visualize the Berry curvature over parameter space. If I sum the Berry ...
5
votes
0answers
37 views
What's the difference between dynamic and static strain aging? [closed]
I do understand how static strain aging occurs and why the yield point comes back if ample time is allotted after a loading and unloading cycles primarily due to diffusion of substitutional and ...
8
votes
2answers
175 views
What will break the time-reversal symmetry?
Specifically, I am interested in the time-reversal symmetry $(\mathcal{T})$ in quantum mechanics. The $\mathcal{T}$ is considered as an anti-unitary operator, namely:
$$\mathcal{T}\psi(\vec{r},t)=\psi^...
5
votes
1answer
57 views
elastic constants transformation/basis change P21/a -> P21/n
I just calculated the stiffness tensor for a given material (a monoclinic molecular crystal)
using molecular simulation. When trying to compare my results to published experimental results
I found ...
16
votes
12answers
8k views
Is it better for me to study chemistry or physics?
I might decide to pursue material science.
Aptitude and background
I am from the UK, and for A-levels, I am studying Maths, Further Maths, Physics and Chemistry, and I am predicted decent grades in ...
8
votes
0answers
130 views
Can we calculate bond enthalpies for each bond in a supercell of a disordered AB crystal using DFT? [closed]
Apart from using Bader charge analysis or energy of formation estimation, I wonder if there is a way to compute the bond energy of constituent bonds in a crystal using density functional theory.
Let's ...
8
votes
1answer
1k views
What is the physical meaning of occupations='smearing' in Quantum ESPRESSO?
I want to understand, what is the intuition behind using the occupations='smearing' or 'tetrahedra' in Quantum ESPRESSO input file? I mean how we can interpret what is going to happen inside of ...
7
votes
2answers
70 views
Combined effects of strain and doping on the electronic structure of semiconductors
I've read papers in DFT studies on band gap tuning in semiconductors and the usually studied methods are either through doping or application of external strain. But it is always just one or the other....
10
votes
1answer
2k views
How to understand the crystal field splitting of d-orbitals in a trigonal prismatic geometry?
This question is coming from this paper, which investigated the spontaneous spin and valley polarizations of monolayer LaBr2.
The geometric information of monolayer LaBr2 is displayed as following (Br:...
10
votes
2answers
276 views
Morse potential for phonons in solids instead of the harmonic potential approximation?
As the title says, the Morse potential (https://en.wikipedia.org/wiki/Morse_potential) is an exactly solvable model in quantum mechanics, just like the quantum harmonic oscillator. Extensions of it ...
8
votes
1answer
420 views
How to perform virtual crystal approximation calculations in VASP?
Can someone share appropriate tags and methods to perform virtual crystal approximation calculations in VASP?
8
votes
1answer
177 views
How to calculate the orthogonal representation of a HCP cell?
I'm trying to write a program to calculate the neighbor lists of crystal systems. I found a few codes that are able to calculate it for orthogonal systems. How can I do it for non-orthogonal cells ?
...
10
votes
0answers
71 views
What are the methods of modeling Jahn-Teller effects in a solid-state material? [closed]
The Jahn-Teller effect arises from the symmetry breaking (distortion) of the local environment for the crystal field of 3d transitional metal ions.The distortion result in energy saving of electronic ...
9
votes
0answers
113 views
Is the non-trivial band topology in a system, caused by spin-orbit-coupling or band inversion? [closed]
How can we know that the non-trivial band topology in a system is driven by spin-orbit coupling (SOC) or by band inversion?
Based on my understanding, SOC causes the band inversion and makes the ...
6
votes
1answer
80 views
Charge density wave and band inversion
Is there any connection between charge density wave and band inversion? Or is there any system in which band inversion follows the same mechanism as the CDW? I am just trying to find a connection ...
14
votes
0answers
178 views
Why does the Wolff algorithm slow down in a 4-body Ising model?
In the paper that introduced "Self-learning MC" (an ML-inspired MC technique, as I understand) the authors consider a many-body Ising model as an example to show the efficiency of their ...
12
votes
1answer
167 views
Ising models with many-body interactions
I find it surprisingly difficult to find researches/papers on systematic "many-body interaction" extensions of the Ising model. Can somebody tell me a good review/article etc on this matter ...
15
votes
5answers
442 views
What are some open-source all-electron DFT alternatives to Wien2K?
Since the beginning of the century, Wien2K has proven to be a very powerful player in computational condensed matter and materials physics.
Wien2K is an all-electron periodic DFT code based on the ...
13
votes
1answer
1k views
Labeling of high symmetry points in Brillouin zone
A Brillouin zone is defined as a Wigner~Secitz primitive cell in the reciprocal lattice [1,2].
The construction of the first Brillouin zone for two different 2D lattices are shown below:
The ...
20
votes
1answer
148 views
What class of materials are closest to realizing the tunable coupling Hamiltonian?
From a physics point of view, there is an effective (approximation to second-order coupling Jaynes-Cummings) Hamiltonian of the form [1]
\begin{equation}
H=\sum_j\omega_j(t)\sigma_j^z+\sum_{\langle i,...
