FDGod's user avatar
FDGod's user avatar
FDGod's user avatar
FDGod
  • Member for 11 months
  • Last seen this week
7 votes
Accepted

What are "completely positive" and "CPTP" quantum maps?

5 votes
Accepted

What is the expression for $|\psi\rangle\!\langle\psi|$ if $|\psi\rangle=\cos(\theta/2)|0\rangle+\sin(\theta/2)e^{i\phi}|1\rangle$?

5 votes
Accepted

What is the relation between maximally entangled and maximally mixed?

5 votes
Accepted

Resources to study superconducting quantum hardware for beginners

5 votes
Accepted

What information about the logical state does one obtain from the stabilizers?

5 votes

Are measurements in $X$ and $Z$ bases being equal enough to prove equality of quantum states?

4 votes
Accepted

Are GHZ states absolutely maximally entangled?

4 votes
Accepted

Python package for quantum computations based on symbolic variables

4 votes
Accepted

Prove the fidelity equals $F( \rho , \sigma) = |\langle \psi_{\rho} | \psi_{\sigma}\rangle|^2$ for pure states

4 votes

Resources for understanding non-unitary channels and operators

4 votes
Accepted

How to create a maximally entangled state of two 4-level quantum mechanical systems?

4 votes
Accepted

How to prove the matrix identities $HXH = Z$ and $HZH = X$?

3 votes
Accepted

How to get a state vector from bloch sphere coordinates for 1 qubit?

3 votes
Accepted

Are equiprobable state same as superposition state

3 votes
Accepted

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

3 votes
Accepted

Is the full quantum circuit always in a pure state?

3 votes
Accepted

Distance of concatenated codes: a counter example?

3 votes
Accepted

Trace Distance in Bloch sphere, what is the vector of Pauli matrices?

3 votes

How is the $\text{CNOT}$ gate equivalent to $\text{XOR}$?

3 votes
Accepted

How can I calculate the measuring probabilities of a two qubit state along a certain axis?

3 votes

Is purity an entanglement witness?

2 votes
Accepted

Ancilla qubit error spreading to multiple data qubits?

2 votes
Accepted

Are the logical states of the corresponding unencoded state unique?

2 votes

Is there a measure for entanglement of $n$-qubit system?

2 votes

In the phase flip action on standard basis, why do we consider the $-1$ phase only for the $|1\rangle$?

2 votes

Prove that $\text{Tr}(M|ψ\rangle\langleϕ|)=\langleϕ|M|ψ\rangle$

2 votes
Accepted

QuTiP ptrace function results do not recreate original composite system

2 votes

Why does Lidar define a decoherence-free subspace as "a subspace that undergoes purely unitary evolution"

2 votes

Does the $\text{CNOT}$ gate activate if the control qubit is $-|1⟩?$

2 votes

Generating All Logical Clifford Operators in Stabilizer Codes via Coset Multiplication