The Collapse Before a Quantum Jump Transition

Abstract

We may infer a transition $|n⟩\to |m⟩$ between energy eigenstates of an open quantum system by observing the emission of a photon of Bohr frequency ${\omega }_{mn}=(E_n-E_m)/\hslash$. In addition to the "collapses" to the state $|m⟩$, the measurement must also have brought into existence the pre-measurement state $|n⟩$. As quantum trajectories are based on past observations, the condition state will jump to $|m⟩$, but the state $|n⟩$ does not feature in any essential way. We resolve this paradox by looking at quantum smoothing and derive the time-symmetric model for quantum jumps.

4 pages, 2 figures

References in corpus (2)

• Time-Symmetric Quantum Theory of Smoothing
• On the Stochastic Limit of Quantum Field Theory

Cited by in corpus (1)

• Generalized conditional expectations for quantum retrodiction and smoothing