Podcast
Questions and Answers
What type of materials contain large densities of free electrons, leading to a strong contribution to the dielectric function?
What type of materials contain large densities of free electrons, leading to a strong contribution to the dielectric function?
- Metals and lightly doped semiconductors
- WTO Al2O3 materials
- Metals and heavily doped semiconductors (correct)
- Optical media and insulators
In a free electron plasma, what happens when the free electrons interact with electromagnetic radiation?
In a free electron plasma, what happens when the free electrons interact with electromagnetic radiation?
- They exhibit a strong restoring force
- They behave like atomic oscillators
- They experience a zero restoring force (correct)
- Their polarization is independent of the electric field
What formula can be used to calculate the dielectric function of a metal or a doped semiconductor?
What formula can be used to calculate the dielectric function of a metal or a doped semiconductor?
- Atomic oscillator formula
- Plasma frequency formula
- Clausius-Mosotti formula
- Drude-Lorentz formula (correct)
In an ideal metal with zero damping, what is the behavior of the plasma frequency?
In an ideal metal with zero damping, what is the behavior of the plasma frequency?
Why are metals transparent in the UV region?
Why are metals transparent in the UV region?
What characterizes the dielectric function of a free electron plasma?
What characterizes the dielectric function of a free electron plasma?
What induces a current density J in a metal during a time-varying field?
What induces a current density J in a metal during a time-varying field?
In the equation of motion for free electron plasma, what does the symbol 'g' represent?
In the equation of motion for free electron plasma, what does the symbol 'g' represent?
What is the relationship between momentum scattering time and momentum loss in free electron plasma?
What is the relationship between momentum scattering time and momentum loss in free electron plasma?
How does the velocity v(t) in free electron plasma behave with respect to time?
How does the velocity v(t) in free electron plasma behave with respect to time?
What does the dielectric function of a free electron plasma represent?
What does the dielectric function of a free electron plasma represent?
Which term in the equation Ne 2 / s(w) represents the AC conductivity in free electron plasma?
Which term in the equation Ne 2 / s(w) represents the AC conductivity in free electron plasma?
What type of transitions occur in semiconductors during inter-band transitions?
What type of transitions occur in semiconductors during inter-band transitions?
How can mid-bandgap states in wide bandgap materials be created for optical activity?
How can mid-bandgap states in wide bandgap materials be created for optical activity?
What gives metals their characteristic shiny appearance?
What gives metals their characteristic shiny appearance?
In which part of the spectrum does free carrier absorption typically occur in semiconductors?
In which part of the spectrum does free carrier absorption typically occur in semiconductors?
What is a common method to introduce 'Colour centres' in materials like sapphire?
What is a common method to introduce 'Colour centres' in materials like sapphire?
What is a characteristic feature of the optical response of all insulators and semiconductors?
What is a characteristic feature of the optical response of all insulators and semiconductors?
