Graduate Break points in band structure

Click For Summary
Break points in band structure refer to the intersections of energy bands in a plot of energy versus wave vector (k). When two bands intersect, the lower energy band is indexed as having a distinct energy profile, which can create sharp edges or discontinuities in the band structure, particularly evident in Dirac cone structures. This phenomenon indicates that the energy levels are not smoothly varying but rather exhibit abrupt changes at the intersection points. The discussion emphasizes the importance of understanding these break points for analyzing electronic properties in solids. Overall, the concept is crucial for interpreting the behavior of materials at the quantum level.
chikou24i
Messages
44
Reaction score
0
What do we mean by break points in band structure ? and what that sentence means : "if the band index were chosen in such a way that the energies are indexed in ascending order for any k then break points would appear in the εnk vs. k plot (with n fixed) wherever two lines intersect." ?
Reference: [Jenö_Sólyom,_A._Piróth]_Fundamentals_of_the_Physics of solids Volume II, page 85
 
sorry, I didn't understand what you have said.
 
chikou24i said:
sorry, I didn't understand what you have said.

Maybe I'm wrong, but I think that it's trying to describe what happens when 2 bands intersect. If 2 bands intersect, and you index band 1 has the "lower energy" band, and band 2 as the higher energy band

$$\epsilon_1(k)$$ would look like a surface with sharp edges (discontinuous) for dirac cone type structures. Maybe the dirac cone is a break point?

https://www.google.com/search?q=dir...=OcL_Vtm9POmpjgTwlbHwDw#imgrc=FS6VEyJMufMagM:
 
  • Like
Likes chikou24i
Thread 'Unexpected irregular reflection signal from a high-finesse cavity'

Thread 'Unexpected irregular reflection signal from a high-finesse cavity'

I am observing an irregular, aperiodic noise pattern in the reflection signal of a high-finesse optical cavity (finesse ≈ 20,000). The cavity is normally operated using a standard Pound–Drever–Hall (PDH) locking configuration, where an EOM provides phase modulation. The signals shown in the attached figures were recorded with the modulation turned off. Under these conditions, when scanning the laser frequency across a cavity resonance, I expected to observe a simple reflection dip. Instead...
View full post »

Similar threads

Undergrad What k states are occupied in a band
  • · Replies 2 ·
Replies
2
Views
2K
Undergrad Built-in potential in pn junction
  • · Replies 2 ·
Replies
2
Views
4K
Where are the high symmetry points on a graphene band structure?
  • · Replies 3 ·
Replies
3
Views
8K
Why do we need Gamma point in Band structure
  • · Replies 1 ·
Replies
1
Views
8K
Group Theory to Understand Band Gap Structure of Semiconductor Oxides
  • · Replies 1 ·
Replies
1
Views
5K
Graduate Diffraction on periodic Structures
  • · Replies 32 ·
2
Replies
32
Views
5K
[PoM] Electrons Fermi level in a crystal
  • · Replies 8 ·
Replies
8
Views
2K
Graduate Fine structure and fixed points
  • · Replies 16 ·
Replies
16
Views
6K
Atomic displacements, replacements, and radiation damage of structural materials
  • · Replies 1 ·
Replies
1
Views
1K
Structure of the Galaxy: 6 Questions Confirmed
  • · Replies 31 ·
2
Replies
31
Views
4K