Particle in 3D Box: Relation between Ω(E) and E

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SUMMARY

The discussion focuses on deriving the relationship between the number of accessible states, Ω(E), and energy, E, for a single particle in a three-dimensional box of volume L³. The relevant equation is E = ((π²ћ²)/(2mL²))(nx² + ny² + nz²), which leads to the conclusion that nx² + ny² + nz² = (2mEL²)/(π²ћ²). To find the number of states with energy less than E, ψ(E), participants suggest using a volume integral to approximate the sum over states, ensuring that the quantum numbers n_i are greater than zero.

PREREQUISITES
  • Understanding of quantum mechanics, specifically the particle-in-a-box model.
  • Familiarity with the concepts of energy quantization and accessible states.
  • Knowledge of spherical coordinates and volume integrals in three dimensions.
  • Basic proficiency in mathematical physics, particularly in handling equations involving π, ħ, and mass.
NEXT STEPS
  • Explore the derivation of the density of states in quantum mechanics.
  • Study the application of volume integrals in calculating accessible states.
  • Investigate the implications of quantum numbers in particle confinement scenarios.
  • Learn about the statistical mechanics approach to energy distributions in quantum systems.
USEFUL FOR

This discussion is beneficial for physics students, particularly those studying quantum mechanics, as well as educators and researchers interested in statistical mechanics and the behavior of particles in confined systems.

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Homework Statement


For a system consiting of a single particle of mass m in a box of volume L^3 (Lx = Ly = Lz = L) develop a relation between the number of accessible states, Ω(E) and E


Homework Equations


E = ((π^2ћ^2)/(2mL^2))(nx^2 +ny2 +nz2)


The Attempt at a Solution



nx^2 + ny^2 + nz^2 = (2mEL^2)/(π^2ћ^2)

this is the equation of a sphere. The next step would be to find the number of states with energy inferior to E (ψ(E)) but I'm a bit clueless about how to do that with the equation. Could someone clarify that for me? Thanks in advance
 
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If you can assume that the radius of the sphere is much larger than 1, you can use a volume integral to approximate the sum over states. You must be careful that your counting respects that the n_i>0.
 

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