Solid State Physics

This is the first of a 2-part review for the final exam. HREF="http://128.210.157.22:1013/Boilercast/2006/Spring/PHYS545/0101/PHYS545_...

A metal in a magnetic field has its Fermi sea sectioned into onion-like layers, shaped like cylinders. These are Landau levels, due to the ...

There are many more phases of matter than solid, liquid, and gas. Superconductivity is a different phase of matter, and superconductors in t...

When superconductors go superconducting, the energy gain is called the condensation energy. Lecture Audio

The quantum stability of a superconductor ensures that electrons can carry current perfectly, without losing energy. There are 2 ingredient...

We finish off the low temperature corrections to the magnetization in a ferromagnet due to spin wave excitations, and also calculate the ene...

We started off today with a demonstration of Barkhausen Noise in ferromagnets. (Your refrigerator magnets are ferromagnets.) If you've ...

Ferromagnets spontaneously break a continuous symmetry -- that is, when the net magnetization develops, it must choose a particular directio...

How many electrons get polarized when you apply a magnetic field to a metal? Is it all the electrons inside the Fermi surface? It turns ou...

Magnetic moments in a solid come from the electronic spin, and also its orbital angular momentum. We review how the orbital angular moment...

Paramagnets have magnetic moments whose directions fluctuate wildly with temperature. But, if you apply an external magnetic field, you can...

There are many flavors of magnetism in solids. You're probably most familiar with ferromagnets (like your refrigerator magnets). In th...

We derive the Einstein relations, which connect the conductivity with the diffusion coefficient. This is far more exciting than it sounds, ...

We answer that question: can you use a p-n junction to run a light bulb? More about the p-n junction: thermal equilibrium, and recombinat...

We talk more about holes today. They don't really exist, you know! But when only a few electrons are missing from the valence band, it...

Today is all about semiconductors. We talk about how to dope them. Donor atoms "donate" electrons into the conduction band, givi...

Electronic energy levels in simple crystalline solids have a bandstructure to them. (Bandstructure is just energy vs. wavevector or momentu...

We solve for the electronic states in a 1D crystal in the "tight binding" approximation. Rather than starting from the box of fr...

Have you ever wondered how electrons can sneak through a metal and conduct electricity with all those atoms in the way? It's Bloch'...

We give some intuition today about when you should expect the Wiedemann-Franz ratio (which relates the electrical to the thermal conductivit...

Today, we derive the electronic heat capacity in metals. This gives a contribution to the heat capacity that is linear in temperature. Ph...

The Debye approximation is a way of calculating phonon properties. Here's the approximation: 1. Pretend the phonon dispersion is linear....

We define the heat capacity, and calculate the phonon heat capacity in the high and low temperature limits. We also introduce the density o...

We discuss generalities of phonon spectra. These include: frequency goes to zero at the reciprocal lattice vectors; group velocity goes to...

We review lattice planes, and talk about how to construct the corresponding Miller indices. We define the reciprocal lattice: Think of thi...

A lattice is a regular arrangement of an infinite set of points in space. A Bravais lattice is one where every point looks the same as every...

Reductionism is the idea that by breaking things into their smallest constituents, we will learn all about them. For example, we might want...