(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

IfUis a 2 x 2 unitary matrix withdetU=1. Show that|TrU|≤2. Write down the explicit form ofUwhenTrU=±2

2. Relevant equations

Not aware of any particular equations other than the definition of the determinant and trace.

3. The attempt at a solution

I have attempted this problem in several different ways to no avail. I'm pretty sure that the explicit form ofUwhen the trace is 2 is simply the 2 x 2 identity matrix.

I do know that

Tr(AB) ≠ Tr(A)Tr(B)

and

U*U = I

but not sure where to go with this.

Any help is greatly appreciated.

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# Homework Help: Relationship between Trace and Determinant of Unitary Matrices

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