Questions tagged [condensed-matter]

For all matters related to condensed matter physics.

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3
votes
1answer
37 views

How to simulate a furnace computationally

I am trying to synthesize MoSe$_2$ crystals in a furnace with two temperature zones. The problem is that the oven is not very wide, so the temperature of the hottest zone influences the temperature of ...
6
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0answers
21 views

Symmetry of glide planes

I am trying to understand the symmetry elements of space group number 194 (P$6_3$/mmc), which is hexagonal and has 24 symmetry operations. In the table of symmetry operations it says that it has three ...
4
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0answers
29 views

Structural biology vs condensed matter prediction

I have two main modeling research lines: one related to structural biology (including rational drug design, de novo design, polymorphism, etc.) and the other one related to condensed matter (...
12
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2answers
78 views

What are real examples where fractals were used in Matter Modeling?

A fractal is, accordingly Oxford English Dictionary: A curve or geometric figure, each part of which has the same statistical character as the whole. Fractals are useful in modeling structures (such ...
13
votes
1answer
116 views

Can we “invert” Density Functional Theory through sufficiently accurate experiment?

The famous Hohenberg-Kohn theorems say that there is a one-to-one mapping between the many-body Hamiltonian, $\mathcal{H}$, of a solid and its ground-state electron density $\rho(\mathbf{r})$. As far ...
10
votes
1answer
55 views

What are some codes available for Dynamical Mean Field Theory (DMFT)?

One particularly field of matter modeling is that of strongly correlated materials, heavy-fermion compounds with partially filled 4f or 5f orbitals. In brief, these are materials whose complex ...
5
votes
1answer
31 views

Property related with Berry curvature: $\Omega_{n,\mu\nu}=-\Omega_{n,\nu\mu}$

I read in David Vanderbilt's book named "Berry Phases in Electronic Structure Theory - Electric Polarization, Orbital Magnetization and Topological Insulators" the definition of Berry ...
13
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1answer
600 views

How to understand time reversal symmetry in graphene

A lot of references say that the Dirac cone in graphene is protected by inversion and time reversal symmetries. How can one understand this statement? How can one show explicitly that the gapless ...
11
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1answer
84 views

Real space projection vs reciprocal space projection in DFT calculations

When doing VASP calculations for large cells, we get a warning: "You have a (more or less) 'large supercell' and for larger cells it might be more efficient to use real space projection ...
16
votes
1answer
125 views

Difference between potential energy, free energy and Coulomb energy in solid state physics

I often encounter terms such as (Helmholtz, Gibbs) free energy, potential energy and total energy when describing the energy of a physical system at atomic level. Sometimes I stumble upon Coulomb ...
11
votes
2answers
122 views

How to convert Unified Pseudopotential Format (UPF) into Ultrasoft Pseudopotential (USPP) format?

I am working on DFT code having plane wave along xy axis and bspline in z direction. For calculating the properties of TMD materials, spin orbit coupling must be included but i did not find fully ...
13
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2answers
450 views

How much does the initial geometry affect the final geometry in optimization calculations?

This might be a stupid question but to what extent will the initial configuration of a bulk phase geometry optimization calculation affect the final geometry? Most places say to start with ...
8
votes
1answer
63 views

2D Brillouin zone generator

There are several pages where you can find scripts/simulations to generate the first Brillouin zone for square and hexagonal 2D lattices. I wonder if there is a tool to generate the Brillouin for ...
11
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0answers
41 views

How to find the projected Hamiltonian for lowest flat-band in general?

In [1], starting with the bosonic Hamiltonian (Eqn. 1) for the dice lattice model with half flux density (with Ahronov-Bohm phases incorporated), \begin{equation} H=-t\sum_{\langle j,\mu\rangle}(a^\...
9
votes
1answer
75 views

What is the difference between U(1) and O(2) symmetry?

To my understanding, they both refer to circular symmetry. I know U(1) is the complex plane, and I think O(2) is real numbers. I have seen them used more or less interchangably, but is there actually ...
19
votes
2answers
285 views

What significant matter modelling methods are implemented in commercial software, for which there is no freeware alternative?

There is an ever-growing list of freeware and open-source software for solid-state physics and quantum chemistry. But many commercial programs still thrive, even in 2020, and their cost can be in ...
14
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1answer
50 views

What are good resources to study crystallographic defects in different dimensional systems and their topological dimensionality?

I wonder if there are any books or resources that may address one or more of the following questions: What kinds of defects are important for topology? Especially crystallographic defects. How do ...
20
votes
1answer
115 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,...
16
votes
1answer
67 views

What exactly is a topological insulator and how to recognize one from band structure?

Four years ago, the Nobel Prize in physics was awarded for "for theoretical discoveries of topological phase transitions and topological phases of matter." In line with this, I heard of topological ...
19
votes
1answer
99 views

What is the importance of electron interaction on dielectric response of crystals?

After obtaining the Kohn-Sham orbitals from a plane-wave-based self-consistent-field calculation, the dipole matrix elements could be calculated in order to determine electro-optical properties such ...
15
votes
1answer
73 views

Functionals/basis sets optimized with respect to properties?

In general (at least for molecular calculations) basis sets and DFT functionals are fit to some high level calculation or experimental energy. It is speculated that an accurate energy will result in ...
19
votes
2answers
133 views

Is there a list of all universality classes for phase transitions with examples of each?

I've often had this problem: I have a model that has a phase transition in it, but I don't know what universality class it falls into or what the universality class is called. Is there anywhere on ...
24
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0answers
172 views

Where/when did the fields of Operations Research and Materials Modeling begin to cross-pollinate? [closed]

Operations Research is a field of mathematics in which optimal or near-optimal solutions are sought for complicated problems. In the modeling of materials, we often optimize Ising models, in which the ...