In quantum mechanics, regarding light (photon), how to tell that a wavefunction is in a pure state or mixed state?(adsbygoogle = window.adsbygoogle || []).push({});

I am learning these stuffs for my first time.

I have attempted to answer that question but I am not sure: a wavefunction can be wrtitten as a linear combination of linear independent vectors, i.e

[itex]\Psi[/itex]=[itex]\alpha[/itex][itex]\Psi[/itex][itex]_{1}[/itex]+[itex]\beta[/itex][itex]\Psi_{2}[/itex]

Where [itex]\Psi[/itex] is the wavefunction, [itex]\Psi[/itex][itex]_{1}[/itex] and [itex]\Psi_{2}[/itex] are unit vectors that form a basis, [itex]\alpha[/itex] and [itex]\beta[/itex] are constants.

If this wavefunction is in a mixed state, the sum of [itex]\alpha[/itex] + [itex]\beta[/itex] = 1

Am I thinking right?

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# Mixed state vs. pure state

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