# Questions tagged [kraus-representation]

For questions relating to the Kraus decomposition of quantum channels.

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### Find the Kraus operators for the amplitude damping channel from its isometric representation

I am currently learning about quantum channels and am sadly stuck at a rudimentary problem, where I don't understand how to find the Kraus matrices of a quantum channel. The amplitude damping channel ...
• 41
2 votes
1 answer
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### How many free real parameters in a general CPTP map?

The question is how many free real parameters a general CPTP map can maximally have. Let's assume the CPTP map $\Phi:L(\mathcal{H}_A) \rightarrow L(\mathcal{H}_B)$ is given in the Kraus representation ...
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4 votes
2 answers
213 views

### Prove that if Kraus operators of $\Phi$ form an ONB then $\Phi$ is the replacement map

This problem is from a "passing remark" in this lecture notes. With the help of some colleagues I managed to find a way for this supposedly elementary fact, but I would like to see if there ...
1 vote
1 answer
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### Affine transformation of the Bloch sphere to Kraus representation of qubit channels

It is known that qubit channels can be written in the form: \begin{align} \Phi(\rho) = \frac{1}{2}\left(I+(T\vec{r}+\vec{t})\cdot\sigma\right)\ \end{align} where $\vec{r}$ is the Bloch vector ...
• 21
1 vote
0 answers
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### Completeness relation of kraus operators not satisfied in Fake backends

With the following code ...
• 393
2 votes
1 answer
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2 answers
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0 answers
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### Lindblad under time rescaling: Zero noise extrapolation

This question is related to an earlier post Zero noise extrapolation for error mitigation: Meaning of rescaled density matrix, specifically when there is no local hamiltonian evolution If I have the ...
2 votes
1 answer
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