 Thermofield double state

ID: thermofield-double-state

∣ Ψ_{β} ⟩ = Z (β)^{- 1/2} \sum_{n} e^{- β E_{n} /2} ∣ n ⟩_{L}^{*} ∣ n ⟩_{R} .

Tracing out either copy produces the thermal density operator

e^{- β H} / Z

 New to topics? Read the docs here!