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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Turned to steel in the great magnetic field
This is obviously a "fun" question, but I'm sure it still has valid physics in it, so bear with me.
How great of a magnetic field would you need to transmute other elements into iron/nickel, if ...
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2k views
Reciprocal Lattices
Is there an easy way to understand and/or visualize the reciprocal lattice of a two or three dimensional solid-state lattice? What is the significance of the reciprocal lattice, and why do solid ...
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3answers
562 views
Shine a light into a superconductor
A type-I superconductor can expel almost all magnetic flux (below some critical value $H_c$) from its interior when superconducting. Light as we know is an electromagnetic wave. So what would happen ...
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How Non-abelian anyons arise in solid-state systems?
Recently it has been studied non-abelian anyons in some solid-state systems. These states are being studied for the creation and manipulation of qubits in quantum computing.
But, how these ...
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880 views
Graphene and Klein bottle?
I am trying to understand graphene as a topological insulator.
The spin orbital interaction in graphene is very small (~10mK?). But if we consider that, then graphene should be a topological ...
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2answers
416 views
Is there a method for differentiating fractional quantum Hall states aside from finding Chern numbers?
The ground state for a quantum Hall system on a torus with fractional filling factor can be classified by the Chern number, which is why the Hall conductance is quantized. Is there another method or ...
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Can a superconducting wire conduct unlimited current?
A superconducting wire has no electrical resistance and as such it does not heat up when current passes through it. Non-superconducting wires can be damaged by too much current, because they get too ...
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Is crystal momentum really momentum?
Almost every solid state physics textbook says crystal momentum is not really physical momentum. For example, phonons always carry crystal momentum but they do not cause a translation of the sample at ...
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1k views
What determines the color of a pure substance and is it possible to predict it?
I have always wondered why salt is white, water is clear and gold is, well, gold. What determines the color of a substance? Does it have something to do with the electrons? And is it possible to ...
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317 views
How metallic surfaces states can emerge in topological insulators?
Topological insulators are materials known to have bulk insulator and metallic surface states. But, what is the origin of these metallic surface states? And how the topology of band could help the ...
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332 views
Derivation of the “Bethe sum rule”
I am trying to work out the steps of the proof of the expression: $$\sum_n (\mathcal{E_n}-\mathcal{E_s})|\langle n|e^{i\mathbf{q}\cdot\mathbf{r}}|s \rangle|^2 = \frac{\hbar^2q^2}{2m}$$ from Eq. (5.48) ...
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357 views
Mathematical rigorous introduction to solid state physics
I am looking for a good mathematical rigorous introduction to solid state physics. The style and level for this solid state physics book should be comparable to Abraham Marsdens Foundations of ...
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238 views
Lagrangian of 2D square lattice of point masses connected by springs
Zee's QFT book mentions the Lagrangian of a square 2D horizontal lattice of point masses, connected by springs, and considering only vertical displacements $q_{i}$, as
$ L = \frac{1}{2} ...
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293 views
If I take a handful of salt and wait for an infinite time will it become a single crystal?
That pretty much says it.
Suppose I have some powder of $NaCl$. It is kept in contact with itself in vacuum. You are free to remove all the disturbances that bother you.
Is that true that, well, ...
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173 views
Ferromagnetism with mobile spins
How can electron spins in Iron at room temperature have ferromagnetic order even though they are travelling at very high speeds?
One could argue that spin and motion are completely uncorrelated and ...
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1answer
207 views
Simulating the evolution of a wavepacket through a crystal lattice
I am interested simulating the evolution of an electronic wave packet through a crystal lattice which does not exhibit perfect translational symmetry. Specifically, in the Hamiltonian below, the ...
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344 views
Possibility of Bose-Einstein condensation in low dimensions
I remember having a problem (for practice preliminary exams at UC Berkeley) to prove that Bose-Einstein condensation(BEC) is not possible in two dimensions (as opposed to three dimensions):
For ...
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351 views
Resistance between two points in an infinite metal sphere/cube
Let's imagine that we have a tridimensional metal object of infinite size, and decide to calculate the resistance between two arbitrary points. How would we go about doing this?
I have thought of two ...
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5answers
744 views
Positrons versus holes as positive charge carriers
From Wikipedia: [The Dirac sea is a theoretical model of the vacuum as an infinite sea of particles with negative energy. It was first postulated by the British physicist Paul Dirac in 1930 to explain ...
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Nano-particle or Molecule?
What's the difference between something being labeled a "nano-particle" or it being called a "molecule"?
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How can the Hall effect ever show positive charge carriers?
The Hall effect can be used to determine the sign of the charge carriers, as a positive particle drifting along the wire and a negative particle drifting the other direction get deflected the same (as ...
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925 views
Why are some materials diamagnetic, others paramagnetic, and others ferromagnetic?
Why are some materials diamagnetic, others paramagnetic, and others ferromagnetic?
Or, put another way, which of their atomic properties determines which of the three forms of magnetism (if at all) ...
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423 views
Quantum numbers and the band structure of solids
I got a question concerning the band strucutre of solids.
The reference I'm using is the book on solid state physics by Ashcroft/Mermin.
My problem is that I don't completely understand the reason ...
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211 views
Temperature dependence of resistivity in metals
We know that in high temperature, resistivity in metals goes linearly with temperature. As temperature is lowered, resistivity goes first as $T^5$ due to "electron-phonon" interaction, and then goes ...
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328 views
Number density of LO and LA phonons as a function of temperature?
I'd like to know the how the number density of longitudinal optical (LO) and longitudinal acoustic (LA) phonons varies as a function of temperature of the material. Is there a simple expression for ...
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What are “electron holes” in semiconductors?
I'm tutoring senior high school students. So far I've explained them the concepts of atomic structure (Bohr's model & Quantum mechanical model) very clearly. Now the next topic to be taught is ...
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4answers
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Chemical potential
This is something probably very basic but I was led back to this issue while listening to a recent seminar by Allan Adams on holographic superconductors. He seemed very worried to have a theory at ...
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What is Fermi surface and why is this concept so useful in metals research?
Particularly, I can somewhat appriciate the Fermi energy idea - the radius of Fermi surface which is a sphere. But is there any quantitative use of more complicated Fermi surfaces?
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What is the state of matter of a (solid) yogurt?
Maybe this is a silly question, but I'm not quite sure.
Consider a solid yogurt. Can we assign a specific state of matter to it?
I mean, it behaves like solid. However, if we "mix" it with a spoon, ...
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582 views
Basic Question - Green's Functions in Quantum Mechanics
I am trying to learn about Green's functions as part of my graduate studies and have a rather basic question about them:
In my maths textbooks and a lot of places online, the basic Greens function G ...
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When is use of the 'effective mass' concept appropriate?
In textbooks the characteristic length scale of an exciton, or an electron bound to dopant atom, in silicon is calculated by analogy to the vacuum case.
Bohr radius in vacuum:
$$a_0 = \frac{4 \pi ...
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The Spectral Function in Many-Body Physics and its Relation to Quasiparticles
recently, I stumbled accross a concept which might be very helpful understanding quasiparticles and effective theories (and might shed light on an the question How to calculate the properties of ...
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1answer
444 views
How to calculate the properties of Photon-Quasiparticles
in recent questions like "How are classical optics phenomena explained in QED (Snell's law)?" and "Do photons gain mass when they travel through glass?" we could learn something about effective ...
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Mobile “muonic hydrogen”
If we look at the atomic positions in a single crystal sample with a diamond like lattice, there exist directions along which there are long hexagonal "tubes" (I'm not sure if these have a proper ...
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Yet another question on the Lindhard function
Here's another question concerning the Lindhard function as used in the physical description of metals.
First we define the general Lindhard function in the Random Phase approximation as
...
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Question concerning the Lindhard function
I'm having a question concerning the Lindhard function.
The reference I'm using is the standard text "Quantum Theory of Solids" by Charles Kittel.
I'm concerned with Chapter 6, subchapter "Method of ...
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What prevents bosons from occupying the same location?
The Pauli exclusion principle states that no two fermions can share identical quantum states. Bosons, one the other hand, face no such prohibition. This allows multiple bosons to essentially occupy ...
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Graphene +1 extra carbon bond
I'm not a physicist just a curious mind, so please go easy!
I was just watching a BBC Horizon Documentary that featured a piece on the recently discovered material Graphene. One of the facts ...
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2answers
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How would I calculate the work function of a metal?
In the photoelectric effect, the work function is the minimum amount of energy (per photon) needed to eject an electron from the surface of a metal. Is it possible to calculate this energy from the ...
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maximum positive electric charge of solid body
What are the limiting factors on the positive charge of a solid body? If I assume a 'perfect insulator' environment that would not exchange charge with my solid body, I would guess that I can remove ...
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1answer
506 views
The Difference between Thomas-Fermi Screening and Lindhard Screening
Assuming the general theory of screening related to electron-electron interactions, I was wondering if anyone could provide a clear, yet conceptually complete explanation of the differences between ...
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Why is glass a good conductor of heat?
AFAIK Glass is insulator, it doesn't have free electron. It's said metal is a good conductor of heat because it has free electron, glass doesn't have free electron, why it is a good conductor of heat?
...
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Can surface dipoles/charges change the work function of a metal?
As typically drawn in simplified band diagrams (see picture below), the metal Fermi Level is shown as the top of the conduction band, with the entire band filled.
In many situations, including ...
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1answer
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Can Ohm's law break in metals?
I was rereading Purcell's Electricity and Magnetism as research for another question, and I found this passage:
In metals Ohm's law is obeyed exceedingly accurately up to current densities far ...
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1answer
508 views
Tight Binding Model in Graphene
I'm following a calculation done by a guy who's done it a bit different than what I've done before (used nearest neighbour vectors and a DFT instead of what I will show below), I'm not quite sure how ...
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1answer
237 views
What does “particle number conservation” mean in condensed matter physics?
What exactly does it imply about a condensed matter system to have particle number conserved or not conserved?
For example, why does the superconducting phase break particle number conservation while ...
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What is injection level (semiconductor physics)?
I am currently reading journal articles about semiconductor physics in solar cells. What is injection level?
I'll try to start off with what I understand. Photons hitting the silicon cause its ...
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105 views
Intuition on topologically nontrivial 2D-band structures?
I want to get more intuition on topologically nontrivial band structures.
There's this popular 2D two-band model for a topological insulator
where $H=\sum_{k}h(\boldsymbol{k})$ (see Qi, Hughes, and ...
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1answer
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Where to learn Temperature Dependent Conductivity induced by Electron-Phonon Interaction? [closed]
I want to learn how to calculate the temperature dependent conductivity induced by electron-phonon interaction.
I know in low temperature, the resistance in metal $\rho$ is proportional to $T^5$, $T$ ...
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Order of magnetic phase transitions
Is there any phase transition occur in paramagnetism to diamagnetism transitions state. What should be the order and how will I calculate the order?
