Discussion Overview
The discussion revolves around the derivation of the T1 term in the Bloch equations, specifically questioning whether it can be rigorously derived without coupling the system to a thermal bath. Participants explore the implications of semiclassical scattering and measurement processes in relation to T1, T2, and decoherence.
Discussion Character
- Debate/contested
- Technical explanation
- Conceptual clarification
Main Points Raised
- Some participants suggest that the contribution of semiclassical scattering to the Bloch equations is typically justified using Fermi's Golden Rule, but question if a rigorous derivation is possible without a thermal bath.
- Others argue that T1, T2, and T2* are properties of the system in the absence of measurement and are usually associated with coupling to a thermal bath, raising uncertainty about the meaning of T1 without such a bath.
- One participant points out that the decay of off-diagonal terms in the Bloch equations, attributed to T1, is indeed a form of decoherence, which is typically linked to an environment or bath.
- Another participant questions the necessity of a bath for deriving scattering rates, suggesting that semiclassical perturbations with random phases might yield similar results.
- There is a suggestion that some form of environment is needed for the formalism to apply to open systems, and a belief that deriving T1 without an external parameter is not feasible.
Areas of Agreement / Disagreement
Participants express differing views on the necessity of a thermal bath for deriving T1, with some asserting it is essential while others propose alternative approaches. The discussion remains unresolved regarding the derivation of T1 without a bath.
Contextual Notes
Participants highlight the dependence of the discussion on definitions of decoherence and the role of external environments, as well as the implications of semiclassical scattering in the context of open systems.