It is my understanding that a measurement of [tex] S_z [/tex] followed by a measurement of [tex] S_y [/tex] will result in a particle which is in an eigenstate of [tex] S_y [/tex]. But it appears that a measurement of say [tex] S_y [/tex] followed by a measurement of [tex] S_x [/tex] results in zero. I see this from a question in which im asked to find the expectation value of [tex] S_x [/tex] for a particle in an eigenstate of [tex] S_y [/tex] and my result is zero. But for [tex] S_z [/tex] it is non zero.(adsbygoogle = window.adsbygoogle || []).push({});

I dont understand why this is so. Could someone help me understand why we find non zero [tex] S_z [/tex] values but zero [tex] S_x [/tex] values for a partilce in an [tex] S_y [/tex] eigenstate.

Thanks in advance.

B

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# Homework Help: Measuring Spin - wave function collapse

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