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karry
  • Member for 5 years, 2 months
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3 votes
1 answer
1k views

What is state preparation and measurement errors (SPAM)?

2 votes
1 answer
974 views

How comes the definition of Pauli transfer matrix?

8 votes
2 answers
882 views

How to compute the measurement probability in swap test?

5 votes
1 answer
711 views

What is a maximal entangled multipartite state?

6 votes
1 answer
501 views

Why do we use complex-conjugate instead of complex-conjugate-transpose when calculating the concurrence?

2 votes
1 answer
393 views

Why are Kraus operators $E_k=\langle e_k|U|e_0\rangle$ not just numbers?

0 votes
1 answer
390 views

What is the rank of the pure state?

2 votes
1 answer
228 views

Are $n$-qubit Pauli channels $\mathcal E(\rho)=\sum_j p_j P_j \rho P_j$ invertible?

1 vote
1 answer
211 views

Process matrix of CNOT gate

2 votes
1 answer
204 views

Problem with orthogonal traceless Hermitian matrices

1 vote
1 answer
202 views

How can I represent the completely mixed state as $\frac I2=\frac14(\rho+X\rho X+Y\rho Y+Z\rho Z)$?

3 votes
2 answers
192 views

What do quantum noise models have in common?

2 votes
1 answer
177 views

What is the Choi matrix of the $H$ gate?

3 votes
2 answers
124 views

When should I use the Choi matrix and when should I use the $\chi$ matrix?

1 vote
1 answer
117 views

How to get the quantum process back from its Choi matrix?

2 votes
2 answers
105 views

What we get when measure $|0\rangle$ under computational basis?

1 vote
1 answer
103 views

Why use conjugate not transpose complex conjugate in superoperator?

1 vote
2 answers
95 views

What's the symbol $\circ$ called, and what does it mean?

2 votes
2 answers
95 views

Why density matrix representation usually written in the following form?

2 votes
1 answer
81 views

Is a process matrix of rank $1$ unique?

2 votes
1 answer
80 views

Are POVM elements invertible?

1 vote
0 answers
74 views

Prove $\sum_{ij}(\mathcal{A_G})_{ij}(|\rho\rangle\!\rangle)_j|i\rangle\!\rangle={\cal A}_G|\rho\rangle\!\rangle$ in the Pauli-Liouville representation

0 votes
1 answer
68 views

Derive $\text{tr}((P_A\otimes P_B)\rho_\mathcal{E})=\frac{1}{d}\text{tr}(P_A\mathcal{E}(P_B^*))$

1 vote
2 answers
64 views

Why does the process matrix $\chi$ have dimensions $d^2\times d^2$?

1 vote
2 answers
53 views

What is the difference between the complexity $O$-notation?

3 votes
0 answers
50 views

Why use 576 configurations for two-qubit process tomography?

1 vote
1 answer
48 views

How to unfold the $E= (|I⟩⟩⟨⟨I|+|X⟩⟩⟨⟨X|)^{⊗2}$ and aquire the following equation?

2 votes
1 answer
48 views

How can I compute the probability distribution by using channel through Choi matrix in quantum process tomography?

0 votes
1 answer
47 views

What do the gauge freedom and fix the gauge mean in gate set tomography?

-1 votes
2 answers
45 views

Define a traceless part of $\rho$ [closed]