QM: Problem with an assignment using bra and ket notation

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SUMMARY

The discussion focuses on solving a problem related to the 1-dimensional harmonic oscillator using bra and ket notation. The operators defined are \(\widehat{A} = \alpha (\widehat{a}^+ + \widehat{a}^-)\) and \(\widehat{B} = i\beta (\widehat{a}^2 + \widehat{a}^{-2})\), where \(\alpha\) and \(\beta\) are real numbers. The user successfully calculated \(\widehat{A}|n\rangle\) as \(\alpha (\sqrt{n+1}|n+1\rangle + \sqrt{n}|n-1\rangle)\) but encountered difficulties with \(\widehat{B}|n\rangle\). The community provided guidance on the application of operators to vectors in quantum mechanics.

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Vilashjorthen
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Homework Statement


This problem is about the 1-dimensional harmonic oscillator.
The normalized energy levels are labeled |n>, n=0,1,2...
Two operators are given by

[itex]\widehat{A}[/itex] = [itex]\alpha[/itex] ([itex]\widehat{a}[/itex]++[itex]\widehat{a}[/itex]-)
[itex]\widehat{B}[/itex] = i[itex]\beta (\widehat{a}[/itex]+2+[itex]\widehat{a}[/itex]-2)

where [itex]\alpha[/itex] and [itex]\beta[/itex] are real numbers and [itex]\widehat{a}[/itex]+ and [itex]\widehat{a}[/itex]+ are the step up and step down operators

Calculate [itex]\widehat{A}[/itex]|n> and [itex]\widehat{B}[/itex]|n>

Homework Equations


[itex]\widehat{a}[/itex]+|n> = √(n+1)|n+1>
[itex]\widehat{a}[/itex]-|n> = √(n)|n-1>


The Attempt at a Solution


I have inserted the above equations and got an answer for [itex]\widehat{A}[/itex]|n> (although I am not sure if it is sufficient):
[itex]\widehat{A}[/itex]|n>=[itex]\alpha[/itex] (√(n+1)|n+1> + √(n)|n-1>)
But with [itex]\widehat{B}[/itex]|n> I am stuck at
[itex]\widehat{B}[/itex]|n>= i[itex]\beta (\widehat{a}[/itex]+√(n+1)|n+1> - [itex]\widehat{a}[/itex]-√(n)|n-1>)

Any help will be much appreciated. Thank you in advance.

P.S.: This is my first post, so please let me know if I have posted something "the wrong way".
 
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hey, welcome to physicsforums :)
Your work looks good so far. What is it you are stuck with? In the last line, you have operators acting on something that is a number times a vector. What is the general rule for this?
 

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