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.

learn more… | top users | synonyms

0
votes
1answer
54 views

What are the current carriers in a PN junction?

Imagine a PN junction in forward bias mode. The conventional current goes from the p-side to the n-side. However, as mobile holes move to the n-side, aren't there mobile electrons on the n-side which ...
1
vote
1answer
77 views

What is the difference between Fermi level and Fermi edge?

Just as in title: What is the difference between Fermi level and Fermi edge? My friend makes some research about XPS and he encountered this term. He knows what is Fermi level, but never heard about ...
4
votes
2answers
149 views

For the transition metals, how does counting the number of up-spins and down-spins still give you a non-integer magnetic moment?

The transition metals like Fe, Co and Ni have magnetic moments of 2.2, 1.7 and 0.6 Bohr magnetons, respectively. The band theory says that you get this when you calculate the density-of-states of the ...
1
vote
0answers
50 views

Photon absorption and emission in 2nd quantization

I am looking for models which describe the interaction of matter (lets take a 1D chain of atoms) with photons, especially the emission and absorption. I would love to see the derivation of models in ...
0
votes
2answers
108 views

Why do Weyl points come in pairs in solid state system?

Quoted from "Beyond Band Insulators: Topology of Semi-metals and Interacting Phases" by Turner and Vishwanath: In 3D lattice models, Weyl points always come in pairs of opposite helicity; this ...
0
votes
1answer
43 views

Are deforming force and stress always equal? If they are equal, then why does shape of the body get deformed?

If the deforming force is equal to the restoring force then there is no impact of the deforming force on the body. Then the shape of the body remains constant. How does the body deform, then?
0
votes
0answers
30 views

Numerically evaluating momentum sums

For many-body systems, calculations often involve momentum sums, which are ultimately evaluated numerically for a finite system size $N$. The larger $N$ is, the more accurate the results. Is there ...
0
votes
1answer
42 views

Difference between mechanical modes and phonons

As stated in this review article: Mechanical modes are long compared to the interatomic spacing. It is natural to make the distinction between nanomechanical modes and phonons: The former are ...
2
votes
0answers
23 views

Why are only some materials ferromagnetic? [duplicate]

I've been told in my solid state class, that ferromagnetism occurs when electron spins are alligned. This happens, as I understand it, when it is "energitically favorable" and when the wavefunction is ...
1
vote
2answers
134 views

Why polymeric solids are said to be intermediate between crystalline solids and amorphous solids?

Crystalline solids have ordered arrangement and amorphous solids do not. Polymeric solids are simply formed by the joining of some monomeric units. It has nothing to do with ordered or not ordered ...
0
votes
0answers
31 views

How to escape freeze-out effects of semiconductors in very low temperature

In very low temperature, semiconductors suffer from freeze-out effects. I did see that degenerately doping eliminates freeze-out, but degenerate semiconductors behave like metals. Is/can there ...
0
votes
0answers
39 views

What is ferromagnetism?

Simple question. As far as I've understood it; a ferromagnetic material is one where all the electron spins are alligned parallely - that is, the wavefunction has an antisymmetric spacial part and a ...
1
vote
0answers
24 views

Properties of materials _not_ dependent on fermi surface?

So I'm studying a second solid state physics course where we've covered calculating things like magnetic susceptibility, specific heat and resistivity by considering excitations of electrons around ...
1
vote
2answers
175 views

Why do metals become insulators when oxidized?

I don't know the connection between how forming a new bond with oxygen then changes the density of states to transform the metal into an insulator. It seems like a very powerful transformation.
0
votes
0answers
80 views

Zero Hall coefficient for semiconductors

Is it possible to dope the semiconductors in a way that their hall coefficient is zero?
0
votes
0answers
13 views

Hall coefficient for semiconductors

I read somewhere that hall coefficient for intrinsic semiconductors is zero. But how is that possible because the mobiliities of holes and electrons are never the same?
1
vote
1answer
35 views

What is the relation between Nuclear magnetic resonance (NMR) and electron paramagnetic resonance (EPR)? [duplicate]

It seems to me that the basic principles are exactly the same, right? Then I am puzzled that the former was awarded a nobel prize while the later not. I noticed a similar question here What's the ...
2
votes
1answer
67 views

How do we know that the x-ray pattern is in the reciprocal space? [closed]

I wonder if any one can tell that why do we consider the x-ray pattern (for example, a x-ray pattern on a film for a crystal) in the reciprocal space? (I don't want any explanation about the Ewald ...
2
votes
1answer
37 views

How deep within the sample can the DOS(density of states) be detected by STM(scanning tunnel microscope)?

Using STM equipment, we can get the LDOS(local density of states) on the surface of a sample. I want to know whether the LDOS within the sample(not surface) can be detected by STM. what is the ...
6
votes
2answers
171 views

Is the thermal conductivity of metals affected by magnetic fields?

Especially for a ferromagnet a magnetic field should have a field-induced band shift in the density of states but I wonder if this shift is big enough to be significant and affect the thermal ...
0
votes
0answers
39 views

Is the saturation magnetization of a thin film different if you apply the field at different directions?

I'm getting different values of the saturation magnetization when I measure them in-plane versus out of plane. The saturation magnetization for the out of plane measurement is greater than in the in ...
0
votes
1answer
39 views

Why is the vapor pressure important for people that grow films in high vacuum chambers?

I don't understand what this vapor pressure is. The definition from wikipedia is unclear to me. If I look at two materials and one has a higher vapor pressure than the other, does that mean that the ...
2
votes
1answer
156 views

What is the significance of the Debye temperature from a materials perspctive?

If I look at a table of different metals and their Debye temperatures, what does the variation in these temperatures tell me about these materials?
1
vote
1answer
136 views

Relation between band structure, dispersion, density of states, and the Fermi energy and Fermi level

Despite the long title, this question is mostly qualitative (although I am interested in quantitative results if possible). Say you have an electronic band structure (energy as a function of "k") for ...
0
votes
2answers
109 views

Density Functional Theory (DFT) calculation for metals

Why is DFT not used in calculating electronic structures and properties of metals? I know DFT calculations are not accurate for metallic structures. Can someone explain why?
1
vote
0answers
31 views

Spin flip scattering & Spin dependent scattering [closed]

What causes, i mean the mechanism spin flip scattering & spin independent scattering?
0
votes
0answers
22 views

Band structure and k vectors

If there is a restriction on the allowed states (k vectors) for a system, ie the no of states is equal to twice the number of unit cells in the crystal.. why do we plot k continuously on the x axis? ...
0
votes
1answer
48 views

Why dopant energy levels differ from one material to another?

Dopant levels in Si, Ge and GaAs are very different from each other. Even "similar" materials such as Si and Ge exhibit different dopant energy levels. (source: Pierret, Advanced Semiconductor ...
0
votes
1answer
44 views

What is theMost compressible material commonly found? [closed]

I'd like to know which solid material is highly compressable . I think plastic is widely available and quite compressable. What is something better?
0
votes
1answer
58 views

Elementary introduction to (quantum) hall effect

Where can I find an elementary introduction to classical and quantum hall effect? Only physics I know is some basic quantum mechanics, EM and statistical physics. My goal eventually is to understand ...
0
votes
0answers
23 views

conduction band and free electrons the properties of electrons in conduction band

Do electrons in conduction band consider as free electrons? or they are not completely free? so that we can calculate the distribution function and the density if states ??
0
votes
0answers
35 views

If I know how many atoms I have in a film, can I know the total magnetic moment?

Say I have a Co film and I know its volume so I know the total number of atoms in it. Using this plus the knowledge that each atom has a magnetic moment of 1.7 Bohr magnetons, would the total magnetic ...
2
votes
0answers
52 views

In what cases would using a non-resonant spectroscopy be preferable to using the resonant type?

Here it is mentioned that non-resonant Raman spectroscopy is desirable for avoiding fluorescence and for studying water due to water's low polarizability. How is non-resonant Raman desirable in the ...
0
votes
2answers
304 views

What is the significance of Fermi temperature?

The Fermi temperature of a solid is related to Fermi energy by relation $$ { E }_{ F } ={ k }_{ B }\times{ T }_{ F } $$ where $ { k }_{ B } $ is Boltzman constant. But what is the significance of ...
0
votes
0answers
29 views

Solving Bloch Waves for Potentials with Few Fourier Components

Suppose we have a potential in 1D $$U(x) = 2A\cos(\frac{2\pi}{a} x)$$ Let $G_\alpha$ be reciprocal lattice coordinates $$G_\alpha = \frac{2\pi \alpha}{a},\;\;\;\;\alpha\in \mathbb{Z}$$ As in Ashcroft ...
0
votes
1answer
44 views

Fermi Surfaces meeting

I know the fermi level is the highest energy level in an atom for its electrons and the fermi surface is (in reciprocal space) a sphere of radius fermi level, if that makes sense. So when two ...
1
vote
1answer
42 views

Why Solid Insulators have highest breakdown voltage?

Why does solid insulating materials have a higher breakdown voltage when compared to that of liquids and gases? Can anyone explain this in simple words?
0
votes
0answers
89 views

Particle Hole Transformation of Hamiltonian

The particle hole transformation for a bipartite lattice $\Lambda$ (with sublattices $A$ and $B$) can be written as $$U^\dagger c_{i,\uparrow} U = \epsilon(i) c^\dagger_{i\uparrow} \\ U^\dagger ...
1
vote
1answer
52 views

Sign conventions in Hubbard model

The Hubbard model is often expressed as $$H=-J\sum\limits_{<i,j>} \sum_\sigma c_{i,\sigma}^{\dagger}c_{j,\sigma} +h.c.+U\sum\limits_{i} c_{i,\uparrow}^{\dagger} c_{i,\downarrow}^{\dagger} ...
2
votes
2answers
59 views

What is the mechanism of heat exchange of a bouncing ball?

Imagine a falling ball on a perfectly hard ground. The kinetic energy will be first converted into a deformation of the ball, then the ball will restore it into kinetic and heat energy and recover ...
0
votes
0answers
24 views

Energy magnetization in the presence of temperature and chemical potential gradient

In the following paper (Phys. Rev. Lett. 97, 026603) http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.97.026603 the energy magnetization part of the energy current is given in the presence ...
0
votes
0answers
58 views

Valence bands question

I'm currently doing solid state physics and learning about semiconductors. During the course, I have seen a lot of energy/wavevector graphs, like this one (pic from Kittel): I did not have a ...
1
vote
0answers
41 views

Band-gap for solids with isoelectronic atoms

Isoelecronic atoms have same number of electrons but different nuclear charge. It is said that many of the chemical properties of these elements are equal or at least similar. Can I form solids with ...
0
votes
1answer
656 views

Why are HCP materials brittle whie FCC materials are ductile?

Why are hexagonal close packed materials brittle, While face centered cubic is ductile. Is it related to crystal planes?
0
votes
0answers
19 views

Role of density of states of electrons in a solid

When studying the statistical mechanics of a solid such as a conductor or a semi-conductor, does the density of states of electrons play a role in the calculation of the heat capacities? I know that ...
0
votes
0answers
54 views

Mapping the first Brillouin zone to the nth Brillouin zone

The Brillouin zone can be constructed in the reciprocal lattice, by drawing bisectors to the lines that connect near neighbors. For example in the 2-D square lattice, the first Brillouin zone in red ...
0
votes
0answers
14 views

Why phenomena in different energy scale can be treated separately?

For example, there are electrons and lattice vibration in solid. The order of energy of electron is of eV which is much larger than that of lattice vibration. So they can be treated separately which ...
0
votes
1answer
108 views

Effects of massive magnetic field generated by operation of the large hadron collider?

I read an article about the CERN large hadron collider in which it talks about the magnetic field that is generated while the LHC is operating. A magnetic field more than 100,000 times more powerful ...
2
votes
2answers
85 views

Do metals *really* conduct at zero temperature?

The questions is mostly in the title, but might expose another of my misunderstanding of the band structure of solids and how that leads to metals and insulators. If we have a solid, and the fermi ...
2
votes
0answers
38 views

Landau levels in ferromagnets

Consider a spontaneously magnetised (uniformly) conducting ferromagnet. Now suppose that there is no external magnetic field. The question is as follows: will the motion of electrons be quantized via ...