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Norbert Schuch's user avatar
Norbert Schuch's user avatar
Norbert Schuch's user avatar
Norbert Schuch
  • Member for 6 years, 2 months
  • Last seen this week
3 votes
Accepted

Why don't qubits continuously rotate in the $z$ direction due to free time evolution?

3 votes

Inequality in overlap of quantum states

3 votes

Given $\rho,\sigma$ such that $F(\rho,\sigma)=0$, what can we say about $F(\text{Tr}_A(\rho),\text{Tr}_B(\sigma))$?

3 votes
Accepted

What is the stabilizer group of a $|W\rangle$ state?

3 votes
Accepted

Calculate probability of a state after depolarization

3 votes

Good metaphors for n-level quantum systems

3 votes

Combining Different Qunits

3 votes

What role does the non-commutativity of the tensor product play in experimental quantum computation?

3 votes

How to decompose 4 qubits Toffoli-gate into two-qubits CNOT gate?

3 votes
Accepted

What do entanglement cost and distillable entanglement have to do with measuring entanglement?

3 votes
Accepted

Why can any LOCC operation be written as $\sum_k (A_k\otimes B_k)\rho(A_k^\dagger\otimes B_k^\dagger)$?

3 votes

What is the relation between POVMs and projective measurements?

2 votes

Why is the boundary of the set of states in the generalised Bloch representation comprised of singular matrices?

2 votes

Purity of mixed states as a function of radial distance from origin of Bloch ball

2 votes

Ways in which $\frac{1}{\sqrt 2} (|00\rangle + |11\rangle)$ can be expressed as $\frac{1}{\sqrt 2} (|uu\rangle + |vv\rangle)$

2 votes
Accepted

Finding the maximum number of Q# simulatable qubits

2 votes

Tensor product between operators

2 votes

$R_z$ gate representations

2 votes

Can a Kraus representation act as the identity on any operator?

2 votes
Accepted

Given a channel $\Phi(X)=\sum_k c_k(X)\sigma_k$, are there always $F_k\ge0$ such that $\Phi(X)=\sum_k \operatorname{tr}(F_k X)\sigma_k$?

2 votes

Is there a way to construct a quantum circuit/oracle to check if 2 qubits in an unknown pure state are entangled?

2 votes

Why does one need a non-commuting Hamiltonian for an algorithm to exhibit "quantumness"

2 votes
Accepted

Are two outputs of a quantum operation (CPTP map) themselves related by a quantum operation?

2 votes

Superposition of quantum gates

2 votes
Accepted

What does a "Choi state" where we relax the partial trace condition represent?

2 votes

Prove that for one-qubit unitaries $\text{Tr}|U-V|=2\max_\psi\|(U-V)|\psi\rangle\|$

2 votes
Accepted

Can pairwise entanglement be converted into tripartite correlations?

2 votes

For tetrapartite state, and another way of decomposition, is the Schmidt basis separable?

2 votes

What can we say about $\sum_i K_i K_i^\dagger$ for non-unital CPTP maps?

2 votes

Does the inequality $\mathrm{tr}(L^\dagger L \rho^2)-\mathrm{tr}(L^\dagger \rho L\rho )\geq 0$ hold generally?