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wam_mi
Nov4-09, 02:35 PM
1. The problem statement, all variables and given/known data

Suppose we define states [0] and [1] be the basis which [0] = (1,0) and [1] = (0,1).

There are two things I want to ask. Are the following states product or entangled states?

(i) [Xi] = \frac{1}{2} ([00] + [01] + [10] - [11])

(ii) [Xi] = \frac{1}{\sqrt{10}} ([01] + 3 [10])

2. Relevant equations



3. The attempt at a solution

I understand that [Xi] = \frac{1}{2} ([00] + [01] + [10] + [11]) is a product state, since it can be represented by the tensor products between two qubits. But I just can't see what the answers are for the questions I stated at above. Hm... I guess they're both entangled, am I wrong?

gabbagabbahey
Nov4-09, 03:05 PM
A general two qubit product state is |\Psi\rangle=(\alpha|0\rangle+\beta|1\rangle)\otim es(\gamma|0\rangle+\delta|1\rangle)....Expand the tensor product and equate it to the state you wish to test... are there any values of \alpha, \beta, \gamma and \delta that make that equality hold?