# Tag Info

Accepted

### Equivalence of circuits in measurement-based QC

In step 2, you are doing two measurements, $X$ on qubit 1 and $X$ on qubit 2. To move to step 3, you need to bring these measurements earlier in the circuit, which means updating what they look like ...
Accepted

### Problem with eigenvalue evaluation algorithm application on matrix $U$

TL;DR: Qubit order in the top register is reversed. QFT qubit order in Quirk Quirk's QFT gate treats the top qubit as the least significant and the bottom qubit as the most significant. Thus, if you ...

### Equivalence of circuits in measurement-based QC

If $AU \equiv UB$ then $M_{A} \cdot U \equiv U \cdot M_B$. Measuring $B$ before $U$ is equivalent to measuring $A$ after $U$ if $U$ conjugates $B$ into $A$. The transition from step 2 to step 3 is ...
Accepted

### Constructing a two 3-qubit state involving either X, Y or Z rotation gate

One way to achieve this is the following way. Initialise 1 qubit in the $|0\rangle$-state and rotate along the $Y$-axis to \begin{equation} \frac{1}{2}|0\rangle+\frac{\sqrt{3}}{2}|1\rangle. \end{...

### creating a generalised Bell state with gates

Starting from any of the four basis states, Hadamard + controlled-not will produce each of the four Bell states. So, expressed in terms of the gates you need, you just need to add $X$ to either qubit ...
community wiki Your first bullet is probably correct, although I wouldn't refer to the one single qubit $|0\rangle$ at the top as storing eigenvalues of $A^{-1}$ - the eigenvalues of $A^{-1}$ are ...