I Quantum decoherence vs. measurement process

[timmdeeg]

The decoherence time is extremely short for macroscopic objects like a detector. Does this mean that the outcome of a quantum measurement which happens instantaneous can be understood as being caused by decoherence?

 

[PeterDonis]

The decoherence time is extremely short for macroscopic objects like a detector. Does this mean that the outcome of a quantum measurement which happens instantaneous can be understood as being caused by decoherence?

No, because decoherence does not explain why measurements have single outcomes. It only explains why there is no interference between different outcomes.

 

[.Scott]

The decoherence time is extremely short for macroscopic objects like a detector. Does this mean that the outcome of a quantum measurement which happens instantaneous can be understood as being caused by decoherence?

The detector may be large, but what is important is how much influence a measurement has on the state of the detection system. A detector that captures a photon or other particle without disturbing its spin would not result in decoherence of the spin. Once a measurement has resulted in the movement of a dial or the recording or transmission of measurement data, that measured state is committed - it can be "understood" as decohered.

 

[timmdeeg]

Thanks to both of you for clarifying my question.