For questions related to the unitarity (unitary evolution) of quantum systems, as applicable to quantum computing or quantum information.
Questions tagged [unitarity]
211 questions
2
votes
2 answers
Minimal Circuit Decomposition for a 3 qubit gate
I have this unitary matrix and i need to find the decomposition with the small number of c-not.
I tried to use Quantum Shannon Decomposition but the simple form of the matrix make me think that there is a better decomposition
TheMumens
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1
vote
1 answer
What are rotation angle and axis corresponding to a higher-dimensional unitary?
We know that a single-qubit Unitary can be defined as a single rotation of angle $\theta$ around some axis $\hat{n}$, together with a global phase $\alpha$ (see Nielsen & Chuang Eq. 4.9):
$$ U = e^{i\alpha} R_{\hat{n}}(\theta) $$
My question is,…
David
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1
vote
1 answer
What is the general formula for unitary rotations in terms of Pauli spin operators?
Recently I have read a paper in which they have used a unitary transformation as follows:
$$U_{\frac{7\pi}{16}}=\cos\left(\frac{7\pi}{8}\right)\sigma_{z}+\sin\left(\frac{7\pi}{8}\right)\sigma_{x}$$
Here $ \sigma_{x} $ and $\sigma_{z}$ are the Pauli…
Jasmine
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0
votes
1 answer
How to create a unitary matrix from a circuit
I've been trying to find a way to analytically find the unitary matrix of a circuit, but I cant find the resources to do so. How can I do so?
Thomas Mikhail
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0
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1 answer
Circuit for pre-factors +-i, -1
Setting
I have a (6 qubit) circuit which implements a unitary $U$.
Goal
I need the circuits which implement $-U, iU, -iU$.
Phase matters, because I later embed a controlled version of $\pm i U $ into a bigger circuit.
Attempt
for 3 qubits, Qiskit…
Andreas Burger
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