Superselektor

Superselektor is a term that emerged from a specific context within the discussion of quantum mechanics and information. It refers to a hypothetical device or a specific type of quantum measurement that could, in principle, distinguish between different quantum states with perfect efficiency. The idea is that a superselektor would allow for the selection of a single desired quantum state from a superposition of multiple states, without disturbing the remaining states.

The concept of a superselektor is closely tied to the measurement problem in quantum mechanics. Standard quantum measurements, as described by the projection postulate, inevitably collapse the wavefunction of the system being measured, meaning that the other possible outcomes are no longer accessible. A superselektor, on the other hand, would imply a measurement process that is not only perfectly efficient (detecting the state with certainty if it is present) but also non-destructive for the unselected states.

While a true superselektor remains a theoretical construct, its conceptual existence highlights certain fundamental questions about the nature of quantum measurement, irreversibility, and the potential for information extraction from quantum systems. Research in areas like quantum information theory and the foundations of quantum mechanics continues to explore the implications and limitations related to such idealized measurement processes. The term itself is not widely used in mainstream quantum physics literature outside of specific theoretical discussions.