Help finding electric field for phonon emission.

In summary, The person is asking for guidance with an assignment involving the calculation of electric field for optical phonon emission in a semiconductor with given values for effective mass, optical phonon energy, and mean scattering time. They also mention a hint given in the assignment and ask for help in understanding it. Additionally, they question the feasibility of a 50 meV optical phonon energy and its implications for higher critical temperatures.
  • #1
Johnny_Sparx
16
1
Hello, I seem to be having a problem with an assignment :confused: :

I need to calculate the electric field at which optical phonons will be emitted. Here's what I have been given:
  1. Semiconductor with effective mass m=0.26*m0.
  2. The optical phonon energy is 50 meV.
  3. The mean scattering time is tau=10e-13 s at 300K.

There was a hint given in the assignment as well: "the total kinetic energy of an electron is the sum of hte thermal energy and the acquired energy from the field in the form of drift velocity."

Can I get some guidance here? I am reviewing my notes but some help would be appreciated. Thanks in advance.
 
Physics news on Phys.org
  • #2
an EM wave can interact with a phonon mode of the same frequency and wavevector. As I remember it, frequency of 10**13 sec. corresponds to phonon energy of 40meV.

I doubt if any crystal can have an optical phonon energy of 50 meV? that may be a good news for much higher Tc.
 

1. What is phonon emission?

Phonon emission is the process by which a phonon, which is a quantum of vibrational energy in a solid material, is released or emitted from an atom or molecule in the material. This process can occur due to various factors such as thermal energy or external forces.

2. Why is it important to find the electric field for phonon emission?

The electric field plays a crucial role in determining the behavior of phonon emission. It affects the energy and direction of the emitted phonons, which in turn can impact the thermal conductivity and other properties of the material. Therefore, understanding and accurately calculating the electric field is essential in studying and manipulating phonon emission.

3. How is the electric field for phonon emission calculated?

The electric field for phonon emission can be calculated using various theoretical models and computational methods. One common approach is to use the Boltzmann transport equation, which takes into account the interactions between phonons and the crystal lattice. Other methods include molecular dynamics simulations and density functional theory calculations.

4. Can the electric field for phonon emission be experimentally measured?

Yes, the electric field for phonon emission can be experimentally measured using techniques such as Raman spectroscopy or time-resolved optical spectroscopy. These methods allow for the detection of changes in the vibrational modes of the material and can provide valuable information about the electric field and phonon emission processes.

5. How does the electric field for phonon emission differ from the electric field for electron emission?

The electric field for phonon emission and electron emission are two distinct phenomena that occur in different materials and under different conditions. The electric field for phonon emission is related to the behavior of vibrational energy in solids, while the electric field for electron emission is related to the motion of electrons in a material. The calculations and experimental techniques for each also differ due to the nature of the processes involved.

Similar threads

I Wave in phonon as "forward and backward" movement vs temperature
    • Atomic and Condensed Matter
Replies
4
Views
885
Confused about direction of electric field
    • Introductory Physics Homework Help
Replies
7
Views
1K
A Absorption and emission spectrum in quantum optics
    • Quantum Physics
Replies
4
Views
1K
Electric field in Energy Bands
    • Advanced Physics Homework Help
Replies
1
Views
1K
Capacitor 1/3 filled with a dielectric
    • Introductory Physics Homework Help
2
Replies
40
Views
1K
Surface Current and Electric Field
    • Introductory Physics Homework Help
Replies
1
Views
744
A Physical explanation of time-correlation function and spectrum
    • Quantum Physics
Replies
3
Views
1K
Help me find the electric field vector
    • Introductory Physics Homework Help
Replies
24
Views
2K
Potential Energy of an Electric Dipole in a Uniform Field
    • Electromagnetism
Replies
11
Views
3K
Electric field within a battery
    • Electromagnetism
2
Replies
51
Views
6K

Hot Threads

Recent Insights

Back
Top