Q1. Explain how the density of electronic state depends on the energy in 3D, 2D, 1D and 0D semiconductors. Draw the necessary schemes.
Q2. A bulk magnetic material has a coercivity of 0.01 Tesla, a saturation induction of 0,016 Tesla and a remanence of 0.01 Tesla.
a) Sketch quantitatively the hysteresis loop M vs H, using explicitly the appropriate SI units.
b) Discuss briefly what the physical mechanisms/parameters that can influence those 3 values
c) Explain which application area(s) this material would not be a good choice.
Q3. Explain the giant magneto resistance phenomenon, and its application in spin-valves.
Q4. Write the dispersion law for electrons in graphene. Which consequence has this law for the properties of the electrons?
Q5. Which types of heterostructures can be realized in quantum wires? Illustrate them graphically.