Quantum Mechanics Concepts

104 flashcards by MentisLibrary

Planck and de Broglie relations, the Schrödinger equation, operators and commutators, the hydrogen atom and quantum numbers, the particle in a box and harmonic oscillator, tunneling, measurement and entanglement, spin and statistics, and quantum information. For undergraduate physics students.

What is the Planck-Einstein relation?
E = hf
What is the value of Planck's constant?
h = 6.626 × 10⁻³⁴ J·s
What is the de Broglie wavelength?
λ = h/p
What is the Heisenberg Uncertainty Principle (position-momentum)?
Δx Δp ≥ ℏ/2
What is the Heisenberg Uncertainty Principle (energy-time)?
ΔE Δt ≥ ℏ/2
What is the time-independent Schrödinger equation?
Ĥψ = Eψ
What is the time-dependent Schrödinger equation?
iℏ ∂ψ/∂t = Ĥψ
What is the Hamiltonian operator in 1D?
Ĥ = -ℏ²/(2m) d²/dx² + V(x)
What is the momentum operator?
p̂ = -iℏ d/dx
What is the position operator?
x̂ = x
What is the energy operator?
Ê = iℏ ∂/∂t
What is the commutator of position and momentum?
[x̂ p̂] = iℏ
What is the normalization condition for wavefunction?
∫|ψ|² dx = 1
What is the expectation value formula?
⟨A⟩ = ∫ψ* Â ψ dx
What is the probability density?
ρ(x) = |ψ(x)|²
What is the wave-particle duality?
Particles exhibit both wave and particle properties
What is the photoelectric effect equation?
KEmax = hf - φ
What is the Compton wavelength?
λc = h/(mc)
What is the Compton scattering formula?
λ' - λ = (h/mc)(1 - cos θ)
What is the Rydberg formula for hydrogen?
1/λ = R(1/n₁² - 1/n₂²)
What is the Bohr radius?
a₀ = 4πε₀ℏ²/(me²)
What is the energy of hydrogen atom in Bohr model?
En = -13.6 eV/n²
What is the angular momentum in Bohr model?
L = nℏ
What are the quantum numbers for hydrogen atom?
n (principal); l (orbital angular momentum); ml (magnetic); ms (spin)
What is the orbital angular momentum magnitude?
L = √(l(l+1)) ℏ
What is the z-component of angular momentum?
Lz = ml ℏ
What is the spin angular momentum?
S = √(s(s+1)) ℏ
What is the z-component of spin?
Sz = ms ℏ
What is the Pauli Exclusion Principle?
No two fermions can occupy the same quantum state
What is the fine structure constant?
α = e²/(4πε₀ℏc) ≈ 1/137