Questions tagged [condensed-matter]
For all matters related to condensed matter physics.
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How to understand the 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 ...
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13
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2
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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 ...
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Where/when did the fields of Operations Research and Spin Physics or Molecular Dynamics begin to cross-pollinate?
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 ...
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19
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2
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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 ...
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19
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1
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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 ...
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17
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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^\...
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2
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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 ...
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12
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2
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How can we say that the KS equation is describing a noninteracting many-electron system?
Based on HK's two theorems, the density functional theory was built. Because one can't find the universal energy functional $F_{HK}[n(r)]$, Kohn and Sham further proposed the Kohn-Sham ansatz: mapping ...
- 14.6k
11
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1
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How to use wavefunctions/density to determine which orbitals lead to edge states?
I have a large matrix for a 1D zigzag edge model of an otherwise $3\times 3$ tight-binding Hamiltonian (3 basis functions, each corresponding to an atomic orbital), involving the variable $k_x$. The ...
- 2,131
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How to start with structural defects in monolayer?
First of all, thank you for your help!
You are so helpful every time.
I would like to calculate the influence of the structural defects on the electronic structure in the HfS2 monolayer. With VESTA ...
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How does infinite DMRG work? [duplicate]
iDMRG or infinite-size density matrix renormalization group, is a common technique in condensed matter. It seems that usually people believe that it reliably captures infinite-size behavior. I have ...
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8
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Example of a standard/archetypal/simple 4-band gapped condensed matter model with analytic results? [closed]
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 ...
- 2,131
8
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2
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Are there interesting applications of estimating the energy for generalizations of the Heisenberg model?
I consider that $H$ is a Hamiltonian describing a quantum system of $n$ spin-1/2 particles (or qubits). I assume it can be written as (the $\alpha_k^i$ are real coefficients):
$$\tag{1}H=\sum_{i=1}^3 ...
6
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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 ...
- 2,131