Singular behavior of the density state called a van Hove singularity

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SUMMARY

The discussion centers on the van Hove singularity in the context of a phonon dispersion relation for a monatomic linear chain. The derived expression for the density of states per unit length is given by g(ω) = L/(aπ) * 1/(4C/M - ω²), with the singularity occurring at ω = 2√(C/M). The singularity arises when the denominator approaches zero, leading to an infinite density of states at this frequency, which is crucial for understanding electronic properties in condensed matter physics.

PREREQUISITES
  • Understanding of phonon dispersion relations
  • Familiarity with density of states concepts
  • Knowledge of classical mechanics, specifically mass-spring systems
  • Basic grasp of condensed matter physics principles
NEXT STEPS
  • Study the implications of van Hove singularities in electronic band structure
  • Explore the mathematical derivation of density of states in various systems
  • Investigate the role of phonons in thermal and electrical conductivity
  • Learn about the effects of dimensionality on density of states
USEFUL FOR

Students and researchers in condensed matter physics, particularly those focusing on phonon interactions and electronic properties of materials.

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Homework Statement



I was doing a condensed matter problem (3rd year) of a phonon dispersion relation for a monatomic linear chain. It asked told me to derive an expression for the density state per unit length and I obtained the following:
g(\omega) = \frac{L}{a\p} \frac{1}{4C/M - \omega^{2}}

Homework Equations



The singularity occurs at
\omega = 2(\frac{C}{M})^{1/2}


The Attempt at a Solution


Can someone explain the origin of this singularity?
 
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I understand that a singularity occurs when the denominator becomes zero and hence you get an infinite value for the corresponding function. But how does this relate to the problem?
 

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