Solid-state physics studies how macroscopic properties of solids (mechanical, electrical, optical, etc.) result from their microscopic structure. It usually deals with the scale where quantum properties of the particles are substantial.

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Topological insulators literature

I started learning things on topological insulators and I got lost in dozens of existing papers on this topic. Could anyone recommend me appropriate literature that explains deeply enough what ...
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153 views

Can you explain why crystals form without thermodynamics?

I know that the basic reason that solid crystals form is because it's the lowest energy configuration (i.e. this). I am looking for an intuitive explanation for this process, one that does not involve ...
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85 views

Is the ferromagnetism of iron understood completely?

In Feynman's lecture notes, he said that it is not (at his time). How is the situation today? Can first-principle calculation accounts the ferromagnetism of iron quantitatively now?
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255 views

Why does total spin conservation law forbid the spin wave gap in Heisenberg magnets?

What is the explanation for total spin conservation forbidding the spin wave gap in Heisenberg magnets?
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505 views

When is quasiparticle same as elementary excitation, and when is not?

Can anyone shed light on the comparison between these two concepts?
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Can plasma turn back into gas, solid, or liquid?

I wanted to know if, since basic chemistry teaches you that states of matter can be changed, I was wondering particularly about plasma. I know that virtually all of the Sun is plasma, so I was ...
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Domain of validity for semiconductor equations

If I understand correctly, the distinction between semiconductors and insulators is a matter of convention? A semiconductor is basically an insulator with an (enough) narrow band gap, usually around ...
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524 views

Molecule vs Crystal

Feynman mentions in his lectures: ...the concept of a molecule of a substance is only approximate and exists only for a certain class of substances. It is clear in the case of water that the ...
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397 views

Fermi level with Landau levels

So my question is regarding where the Fermi energy is when you have 2D electron gas in an applied magnetic field. My book explains that, using the Landau gauge, you find that the 2D density of states ...
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845 views

What is different between resolvent and green function

I bumped into a book, where Resolvent $R^{\pm}(E)$ is defined as $e^{\mp iHt/\hbar}=\pm\frac{i}{2\pi}\int_{-\infty}^{\infty}dER^{\pm}(E)e^{\mp iEt/\hbar}$ and $R^{\pm}(E)=\frac{1}{\pm ...
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411 views

What are the applications of delta function potentials?

Are there real applications for using delta function potentials in quantum mechanics (other than using it as an exactly solvable toy model in introductory undergraduate quantum mechanics textbooks) ? ...
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523 views

What is the time correlation function in the Green-Kubo formulation of ionic current?

I am reading a paper, and I came across the Green-Kubo formulation, where the conductivity $\sigma$ of charged particles is related to the time correlation function of the $z$-component of the ...
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Propagation of light in transparent media: absorption and reemission or scattering?

In the two Phys.SE questions What is the mechanism behind the slowdown of light/photons in a transparent medium? and Why glass is transparent? transparent media were discussed. But I'd like to clarify ...
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42 views

Reflection, Transmission, and Plasma Frequency

Does anyone have a good, clear explanation of why and how this works? I don't understand the following. Say you have a piece of metal with a plasma frequency $\omega_p$. This is like a resonant ...
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115 views

Why is Graphene So Strong?

There has been a lot of news about Graphene since its discovery in 2004. And as we are all told it is a revolutionary material which is very strong, conductive and transparent. But what is it about ...
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94 views

Semiconductors and energy bands

The valence and conduction band of a semi-conductor are often drawn as here click. This plot has essentially two features and I would like to understand them. The peak and the valley of the two ...
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495 views

What does “optical conductivity” mean?

Does it just mean "AC electric conductivity"? If so, why have a special name for it, and why mention optical specifically? The wikipedia page on it is very sparse. This (warning, PDF) document just ...
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682 views

Question about the quantization of lattice vibration (phonons)

In my syllabus about solid state physics they state that lattice vibration is quantized, analogous to the harmonic oscillator: $$E = (n+\frac{1}{2})\hbar\omega$$ So the lattice vibration has ...
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48 views

Origin of interaction in inelastic neutron scatting

In solid state physics, inelastic neutron scattering is a commonly-used experimental technique for probing the energy spectrum of phonon and magnon excitations. This technique relies on the ...
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500 views

Nature of tetragonal distortion in Jahn-Teller effect

I am wondering: If I have a regular octahedron as my starting point, oriented along the x-y-z axis, and now Jahn-Teller suggest I elongate or compress along the $z$-axis, what happens along the other ...
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143 views

Why according to Hund's first rule all electron with same spin should occupy orbitals when partially filling?

I get that because of coulomb repulsion initially all the electrons will not occupy the same site but will single occupy the orbitals.But while doing so how do they know to keep their spins aligned ...
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73 views

Periodic momentum space in band structure

I often see pictures like this in physics, this one for Silicon band structure. (source, NB: it's the German page for Silicon). There you see the plot of the energy in terms of the momentum $k$. ...
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388 views

What's the difference between hopping and tunneling?

My professor made a distinction between electron hopping (the closest wikipedia had an article on) and tunneling, saying that one (he didn't say which, but I assume hopping) was temperature dependent ...
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151 views

Group analysis forbids band-crossing in 1D?

Group analysis forbids band-crossing in 1D in terms of conventional band theory. I read this in a good solid state physics book. But there's no explanation at all. Can anyone help on this?
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307 views

Determining Fourier Coefficients by inspection

I'm beginning to learn about Fourier series/transforms. My teacher hopes that by now we should be able to examine a simple potential function and decompose it without having to actually do the ...
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227 views

Can Rydberg states exist within the bulk of a metal?

I am aware that outer shell electrons in rubidium atoms in an optical lattice can be excited to Rydberg levels, in which the electrons orbit well beyond the atoms to which they are bound. Is this ...
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Why is calcium paramagnetic?

As far as I understand, magnetism comes from the 'unpaired electrons' in the subshells of atoms. Atoms with paired electrons are diamagnetic ('not magnetic') while atoms with unpaired electrons are ...
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159 views

From the local Hooke's law to the global one

My system consist of a cylinder with axis Z that can contract and dilate along this axis. It obeys microscopically Hooke's law of elasticity: ...
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48 views

Are there any electro-optic crystals that are also pyroelectric but not birefringent?

As the title says, a crystal that is electr-optic and pyroelectric can it be non-birefrigent?
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166 views

Repulsive classical identical particles on a square lattice

I am not sure whether it is some well-known named model in statistical physics. I could not find it in any standard text-book that I know of. Let there be $N$ identical classical particles ...
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236 views

Experimental samples with rare earth metal

Many experiments, such as optical, superconductivity, etc, use the samples that involve rare earth metals and transition metals. Why are they used that often. Is the main reasons: They have the ...
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33 views

Intuition for the density of states of the free electron gas model

The density of states as a function of energy for a free electron gas (inside some solid-thing where the electrons are modeled due to the free elecetron gas model) is in: 1D: D(E) ~ $\sqrt[-1/2]{E}$ ...
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200 views

Why is Bose-Einstein condensation a phase transition?

Bosons may succumb to a Bose-Einstein condensation at a certain critical temperature $T_c$, thus entering the BEC phase. The only thing I know about the BEC is that since we are talking about bosons ...
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298 views

What does $m^*>m_e$ imply? (the effective mass of electron is larger than its rest mass)

From what I understand, the concept of effective mass is just something people come up with to make electrons and holes obey the equation of motion $$ \vec{F}=m^* \vec{a} $$ without dealing with the ...
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33 views

Why do we still get sharp scattering spots with quasi-crystal?

In a quasi-crystal, there is no translational invariance. This means there is no delta-function in the Fourier transform. But to get a sharp scattering spot, we need a delta function. Physically, ...
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133 views

Statistical Mechanics - Distribution of Energies

Consider a state space $\mathbb{X}$. The probability density function under a canonical ensemble is given by the Boltzmann distribution $$\pi_{\mathbb{X}}(x)=\frac{e^{-\beta ...
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119 views

Possibility of stable muonic structures?

In an analogy to the neutron, which decays rapidly as a free particle, but when bound in a nucleus it is stable, would it be possible to crease a structure that permits the stability of muons - be it ...
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301 views

What determines Phonon - Phonon collisions?

I was in Solid State Physics lecture yesterday and we BRIEFLY went over what causes phonons to collide with one another. Things such as crystal imperfections, boundaries, Temperature, but I was ...
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85 views

Forward-scattering for a single impurity in an infinite system

I'm slightly confused with the following situation: Suppose you have an electron in a tight-binding model, and let's say we are in one dimension with $N$ lattice sites. Add to this a single ...
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264 views

Algorithm for identifying planes in a Bravais Lattice

I have a lattice with Lattice Vectors $(\vec{t}_1,\vec{t}_2,\vec{t}_3)$ which are NOT orthogonal in general. How can I identify the atoms/unit cells that belong to a plane - that is normal to a given ...
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Crystal visualization software for visualizing lattice with reciprocal vectors drawn in same image [closed]

I'm looking for a free crystal visualization program, preferably for Linux, that can visualize the common lattice structures in 3D interactively (rotatable with mouse) and draw in the same picture the ...
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586 views

Thomas-Fermi approximation and the dielectric function (+ small bit on graphene)

1) With the dielectric function, which is a function of wavenumber and frequency,how is it possible to take the limit of either to zero without changing the other one? I thought that frequency and ...
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141 views

Inelastic Scattering and coherent scatterng

Another Scattering Question So I have this Bravais Lattice of sites R vibrating with some normal mode with a small displacement amplitude $u_o$, some wave vector k and some frequency $\omega$. We can ...
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109 views

What is the energy in eV between atoms in a typical solid state material?

Comps 2 question: What is the energy in eV between atoms in a typical solid state material ? Just rough estimate ? How is that related to the thermal energy that needs to be supplied in order to ...
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280 views

How are quantum potential wells fabricated?

Potential wells, such as infinite and finite potential well, have been the standard examples in quantum mechanics textbooks for tens of years. They started being only theoretical toy models but as ...
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696 views

What are Low-lying energy levels?

I am reading about some canonical transformations of the Hamiltonian (of a system consisting of an electron interacting with an ionic lattice) due to Tomanaga and Lee, Low and Pines. One of the ...
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320 views

Lorentz invariance of a frequency- and wavelength- dependent dielectric tensor

Suppose we have a material described by a dielectric tensor $\bar{\epsilon}$. In frequency domain, this tensor depends on the wave frequency $\omega$ and the wave vector $\vec{k}$. Clearly not all ...
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763 views

Madelung constant list (for surfaces as well)

Searching for this on google proved to be quite tedious, but I reckon that someone working with crystals a lot might know this off the top of his head: Is there a good source that lists the Madelung ...
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382 views

Scattering of phonons and electrons within solids

I got a question concerning the scattering of phonons and electrons. I read an introductory explanation to this process that is somehow not very satisfactory. It goes like this: Let $\psi_{k}$ and ...
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Is it possible to have a line rather than a point where the three states of a substance can exist?

Most of us are familiar with state diagrams that define which of the three states a substance will take given the pressure and temperature. And that some substances, such as water for example, exhibit ...