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Anabelle37
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Homework Statement
Evaluate <n|p^2|n>
where p is the momentum operator for the quantised harmonic oscillator.
Homework Equations
creation operator: a+|n>=sqrt(n+1)|n+1>
annihilation operator: a|n>=sqrt(n)|n-1>
The Attempt at a Solution
the operator p can be defined in terms of the creation and annihilation operators, ie. p = (-i/sqrt{2})(a-a+)
I also wrote down that for the quantised harmonic oscillator p = -(ihbar).(partial derivative wrt x) and so p^2= -(hbar)^2.(partial derivative wrt x)^2
I'm stuck on what to do next? How do I evaluate <n|p^2|n> ?
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