# Homework Help: Quick bra-ket question

1. Jan 19, 2012

### StephenD420

|t> + |a> = ?? As an angle from the transition axis

now I know it is 45 degrees is the answer but I am not sure what |t> or |a> equals.
I know |theta> = cos theta |t> + sin theta |a>
so how do I go from here?
Does |t> = cos^2 theta
and |a> = sin^2 theta????

Thanks.
Stephen

2. Jan 20, 2012

### niklaus

Your notation makes no sense to me, maybe you should write down the problem exactly as it was stated?

3. Jan 20, 2012

### StephenD420

What states of polarization do the following states represent(specify by an angle from the transmission axis of the polarizer).
a.

|t> + |a>

4. Jan 20, 2012

### niklaus

I still think I would need much more information to answer this question. Do you use some convention in your class what |t> and |a> mean?

5. Jan 20, 2012

### StephenD420

That is what I am trying to find out

|t> is the transmission quantum state
|a> is the absorbtion quantum state

The lecture started with
|p> = cos theta |t> + sin theta |a>
and
<t|p> = cos theta
<a|p> = sin theta

6. Jan 20, 2012

### StephenD420

bump...

would |t> be cos theta
and |a> sin theta

what would these represent where
|t> + |a> is 45 degrees
|t> + 2|a> is 63 degrees
2|t> - |a> is 27 degrees