6Experiment 6

The Quantum Simple Harmonic Oscillator

Verify the evenly-spaced energy ladder Eₙ = (n+½)ℏω, measure how spacing depends on mass and stiffness, and observe time-evolved superpositions.

A. Energy levels and wavefunctions

500 N/m
0
nEₙ (eV)Eₙ₊₁−Eₙ (eV)nodes
00.179920.359840
10.539770.359841
20.899610.359842
31.259450.359843
41.619300.359844
51.979140.359845

Eₙ = (n+½)ħω, ω = √(k/m). Level spacing ħω is constant — contrast with E ∝ n² for the square well. Click a level to select it.

ψₙ(x) |ψₙ(x)|² V(x) = ½kx²

B. Time development

t = 0.00 fs

Single eigenstate: |ψ|² is frozen. With n+1 mixed: probability density oscillates at beat frequency ω = (E₀₊₁ − Eₙ)/ħ, which here equals the classical angular frequency — because the ladder is evenly spaced.

Observations

Record your measured data in the tables below. Refer to the lab manual for the full procedure.

Table 6.1 — Energy levels and nodes (proton, default stiffness)

nEₙ (eV)Eₙ−Eₙ₋₁ (eV)Nodes

Table 6.2 — Level spacing E₁−E₀ for various settings

SettingE₁−E₀ (eV)

Rows: Increased k; Electron (default k); Proton (default k); Heavy atom (default k)