Question
This model can be used to derive the resonant behavior of materials under optical excitation. For 10 points each:
[10h] Name this classical model that treats the response of a bound charge to incoming radiation as a driven damped harmonic oscillation.
ANSWER: Lorentz oscillator [or Drude–Lorentz oscillator model]
[10e] The Lorentz oscillator is often used to evaluate the dielectric function of materials, which describes the frequency dependence of this quantity. This quantity for the vacuum is a fundamental constant denoted epsilon naught.
ANSWER: dielectric permittivity [accept permittivity of free space]
[10m] The dielectric permittivity of the Lorentz oscillator has this mathematical property due to the phase difference between the driving field and the system’s response. The form of the index of refraction with this property accounts for both a material’s refraction and its absorption.
ANSWER: complex [reject “imaginary”]
<Physics>
Summary
| 2024 ACF Regionals @ Cornell | 01/27/2024 | Y | 1 | 10.00 | 100% | 0% | 0% |
| 2024 ACF Regionals @ JMU | 01/27/2024 | Y | 9 | 8.89 | 67% | 22% | 0% |
| 2024 ACF Regionals @ Minnesota | 01/27/2024 | Y | 2 | 15.00 | 100% | 50% | 0% |
| 2024 ACF Regionals @ Nebraska | 01/27/2024 | Y | 6 | 10.00 | 83% | 17% | 0% |
| 2024 ACF Regionals @ Rutgers | 01/27/2024 | Y | 5 | 14.00 | 80% | 60% | 0% |
| 2024 ACF Regionals @ Vanderbilt | 01/27/2024 | Y | 5 | 8.00 | 80% | 0% | 0% |
Data
| UNC A (Grad) | GWU B (Grad) | 0 | 10 | 0 | 10 |
| GWU A (UG) | Liberty A (Grad) | 0 | 0 | 0 | 0 |
| William & Mary A (UG) | Liberty B (DII) | 0 | 0 | 10 | 10 |
| UNC D (DII) | Maryland A (Grad) | 0 | 10 | 0 | 10 |
| Maryland B (UG) | JMU A (UG) | 0 | 10 | 0 | 10 |
| UNC B (UG) | Maryland C (DII) | 0 | 10 | 10 | 20 |
| UNC C (UG) | Virginia C (UG) | 0 | 0 | 0 | 0 |
| Virginia A (UG) | Roanoke College A (DII) | 0 | 10 | 0 | 10 |
| Virginia B (UG) | JMU B (UG) | 0 | 10 | 0 | 10 |