# Tag Info

1

Hook and Hall is probably my personal favourite as it is very clear and concise without a lot of fuss. For a totally different style to the classics maybe try "The Oxford Solid State Basics". The lecture notes on which this book was based are available (in part) online (google steve simon solid state lecture notes and you should get there without much ...

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The scales and scopes of the models we do have are far larger than cellular level. Further, while there are skeletal models for animal bodies, the models for their motion is very much top-down modelling rather than bottom-up modelling. That is, an actual human's motions will be recorded and interpolated into the model, or an animator will pose the model in ...

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As a chemist turned engineer, I think I am well placed to answer this question. Does there exist a graphics engine that is as true to our reality as possible given our current understanding of physics? Given appropriate constraints and simplifications, it is possible to build a useful model from simple elements. Whether you consider this "true to ...

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It is an edge dislocation. Compare: to: TEM tracks dislocations in graphene Notice that the yellow loops have 5 and 7 edges, respectively, compared to the usual six.

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Assume also that I have access to an immense amount of parallel computing processing power (I do). Unless you are an important person in the Chinese computational science world (using Tianhe-2), or you have access to secret government computers us mere mortals don't know exist (so they don't appear in rankings of the best supercomputers in the world), I ...

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Anyway, the conjecture is that, possibly if the intensity of the light is strong enough, we can still get photoelectric effect with $\omega < \omega_c$? The frequency treshold for the photoelectric effect is observed with light of common intensities; even very low intensity light will work. There are ways to ionize atoms without such high-frequency ...

1

By absorbing more than one photon an electron can still be detached. However, the probability will be small. On the other hand, using a focussed intense laser beam, the situation improves. In fact, isolated atoms can be ionised in this way. The process is called multi-photon ionisation and has been verfied experimentally.

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I came across this opinion that whenever there is an instance of inhomogenous magnetisation, there is a split in ZFC and FC. In case there is a uniform long range ordering present, the ZFC will fall perfectly on the FC. Does any one have any insights on this view?

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There is a thing called energy, and it is conserved in the sense that if it leaves a region, you now have less of it in that region unless or until some more comes back into the region. If you have some fundamental particles or composite objects they can have different energy based both on their state and how far apart they are from each other. But if they ...

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Well, I know some but not all of the answer numerically. But the main answer is "electromagnetic repulsion" and "Pauli exclusion principle." The nucleus is very, very small compared to the entire atom, so nuclear effects are not much of it. Off the top of my head, I've seen the calculation for how much of the pressure in an ordinary metal (which is basically ...

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The normal nonresonant Raman scattering happens when a photon interacts with a molecule; the molecule absorbs the photon momentarily and re-emits it with slightly less energy. In an energy diagram, that looks like this. The frequency of the incoming photon is $\omega_i$, and the frequency of the scattered photon is $\omega_s$. The thick lined level is ...

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The essential physics, to me, of the energy gap is interference/diffraction of the electron wave. In a very good crystal, like GaAs or graphene, an electron can travel many µm, traversing tens of thousands of atoms. If you consider this classically, it is astounding, as a classical particle would simply collide with the nuclei. However, the reality is that, ...

3

So the fermi-dirac distribution function has the form $$n\left(E\right)=\frac{1}{\exp \left(\frac{E-E_F}{k_bT}\right)+1}$$ So for $E=E_F$ you can see that $n\left(E_F\right)=\frac{1}{2}$ regardless of the value of $T$ so I am not entirely sure what you mean by the first statement in your question. If you plot the FD distribution function at different ...

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Ca2+ is believed to be paramagnetic due to the excitation of one electron from the s-orbital to the emptied d-orbital (s and d orbital are closer in energy, thereby causing transition to occur between both orbitals) which renders the s orbital unpaired in its excited state and attracted to the magnetic field (PAULI PARAMAGNETISM). It is worthy of note that ...

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Magnet's energy doesn't go anywhere. It always stays $\frac{B^2}{2\mu}$ (in some conditions). So where does the work come from, the energy to pull metal to the magnet? If you put piece of iron, or better a wire with flowing current $j$, on distance $d$ from source of magnetic field $B$, then there will be force between two: $\vec F=\vec j \times \vec B(d)$ ...

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because the holes somehow will attract electrons and get them from conduction band to valence band The reason that a p-type semiconductor is p-type is that it contains acceptor impurities. These are atoms that tend to capture electrons in localized states around their nucleus. For example, group III boron is a typical acceptor impurity in silicon. ...

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In a semiconductor, there are contributions to the total electric current from both electrons in the conduction band and holes in the valence band. For N-type material, there are far more electrons in the conduction band than there are holes in the valence band. Thus, almost all of the electric current is due to drift of conduction band electrons. ...

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To obtain the energy gap in the thermodynamic limit, one should take $N\rightarrow\infty, V\rightarrow\infty$ where $N$ is the number of atoms and $V$ the system size, but hold $N/V$ (i.e. density) fixed. In your case, it means simply taking $N$ to $\infty$ is enough and keep all $t, u, \alpha$ fixed for now. This tight-binding model can be solved exactly. ...

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A zero-field-cooled/field-cooled split in the magnetic susceptibility vs. temperature doesn't have to be superparamagnetism. In the case of superconductors, if we apply a field to the material and cool past T$_c$, some flux can be trapped inside, but if we cool first and then apply field, that flux will be shielded away, resulting in greater diamagnetism.

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As I expected, this simple question calls for no more than a little sleight of hand, as pointed out by the sole comment above. It looks as if @Meng Cheng won't make it an answer. Thanks to him. And here I confirm that it works well.

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