Let's say we have photon beam with certain frequency. Now we make a choice to perform one of two noncomuting measurements, say polarization measurement in H/V basis or polarization measurement in +45°/-45° basis. After that measurement we perform frequency measurement.(adsbygoogle = window.adsbygoogle || []).push({});

From QM perspective it is not possible that frequency measurement can commute with both polarization measurements. Therefore we necessarily filter out some photons at least in case of one of two polarization measurements if not both.

Does this reasoning seem correct?

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Commutativity of frequency measurement

**Physics Forums | Science Articles, Homework Help, Discussion**