Quantum Decoherence
Coupling γ
0.05
Env. modes N
6
System freq ω₀
1.0
Temperature T
0.5
Reset Superposition
|ψ⟩ = (|0⟩+|1⟩)/√2 ⊗ |env⟩
After entangling with env:
ρ_S = Tr_E[|ψ⟩⟨ψ|]
Decoherence: off-diag
ρ₀₁ → 0 as |⟨e₀|e₁⟩| → 0
Timescale: τ_D ∝ 1/γ
|ρ₀₁| =
1.000
off-diagonal element
Zurek 1981 · decoherence · pointer states · quantum Darwinism · einselection