Specialized Topics Flashcards
Hydrogen gas bond energy
-4.48 eV
Common lattices
Simple, face centered, and body centered
Conductors, semiconductors, and insulators at absolute zero
- Conductors: All electrons are in conduction band
- Semiconductors: Valence band filled, conduction band nearly empty, but requires less energy than insulators to kick an electron into the conduction band
- Insulators: Valence band filled, conduction band empty
p- and n-type semiconductors
p-type semiconductors are doped with electron acceptors, and therefore have positive mobile charge. n-type semiconductors are doped with electron donors, and therefore have negative mobile charge.
Nuclear magneton
Which stable nucleus has the lowest binding energy per nucleon?
Deuterium
Alpha decay
Release of helium nucleus. Alpha decay occurs when the mass of the original atom is greater than the sum of the masses of the final atom and the neutral helium atom
Decay rate
Two conservation laws in particle physics which do not appear in classical (macroscopic) physics
- Baryon number
- Lepton number
Typical decay times by fundamental force
Interaction signatures
Electromagnetism often emits photons, while the weak interaction often emits neutrinos (and, if one of those particles appears, it must be the mentioned force)
Dual (or reciprocal) lattice
The Fourier transform of the initial lattice
Dual lattices of simple cubic, BCC, and FCC
Simple cubic is it’s own dual. BCC and FCC are duals of one another.
Dual of a hex lattice
The dual to a hexagonal lattice is another hexagonal lattice, but rotated through a 30o angle
Side length of the dual lattice
Interatomic distances in common configurations where the unit cell has side length a
Primitive unit cell of the reciprocal lattice
(first) Brillouin zone
Primitive unit cells for body-centered cubic, face-centered cubic
- BCC: octahedron with half the volume of the conventional cube
- FCC: parallelepipid with a quarter the volume of the conventional cube
Fermi wavenumber
(n is number density of electrons)
Fermi momentum and energy
Electron theory of metals density of states
Number of conducting electrons
Density of states at the Fermi surface
Types of doping
p-type and n-type doping (excess holes or excess electrons, respectively)
Meissner effect
In a weak applied field, a superconductor expels nearly all magnetic flux, meaning that the magnetic field inside is nearly zero. It does so by setting up currents near the surface
Cooper pairs
Part of BCS theory. A cooper pair is a specific state of two electrons, weakly bound to one another, such that the pair has total energy lower than the Fermi energy, which would be the energy of the electrons at low temperature
Universe expansion redshift
Black-body proportionality of the universe
Black-body temperatures are inversely proportional to the ratio of scale factors
Hubble’s law
Redshift as a measure of time
