Top Questions

3 votes
4 answers
37 views

The heart of all of quantum physics is superposition

0 votes
2 answers
16 views

Does $\frac{I + K}{2}\otimes\frac{I+L}{2} = \frac{I+K\otimes L}{2}$ hold for operators $K,L$ acting on different subsystems?

4 votes
1 answer
280 views

Happy 30th Anniversary to Shor's Algorithm! How challenging was the review process when it was first announced?

2 votes
1 answer
286 views

How can the depolarizing channel be a quantum operation?

1 vote
1 answer
37 views

How are qubits actually implemented in terms of hardware?

2 votes
0 answers
14 views

Does no-cloning imply zero capacity of antidegradable channels?

3 votes
0 answers
29 views

Proof that the relative entropy satisfies $S(\rho\|\sigma)=S(T\rho\|T\sigma)$ iff $\hat TT\rho=\rho$, $\hat TT\sigma=\sigma$ for some $\hat T$

4 votes
1 answer
185 views

Can a non-local unitary operator preserve separability

1 vote
1 answer
29 views

Are there standard forms for non-additive quantum codes?

2 votes
1 answer
77 views

Non-linear quantum mechanics and NP-complete problems

4 votes
1 answer
57 views

Can quantum computers help to solve questions of general relativity theory?

1 vote
0 answers
32 views

How to express a traceless matrix in Pauli basis

2 votes
0 answers
39 views

Can we find a product of single-qubit states that is orthogonal to a stabilizer codespace?

1 vote
0 answers
23 views

Adding an Extra Qubit into a Quantum Circuit

2 votes
0 answers
16 views

What are examples of states saturating the strong subadditivity of the von Neumann entropy?

2 votes
0 answers
24 views

How to create a quantum algorithm to determine unknown coefficients in a linear function

11 votes
1 answer
725 views

Does the Quantum Fourier Transform require universality?

8 votes
1 answer
512 views

Is there a comprehensive list of counterexamples in quantum information?

5 votes
1 answer
678 views

Are Quantum Computers Bad at Addition?

3 votes
1 answer
62 views

Where does the "error propagation formula" $(\Delta \theta)^2=(\Delta M)^2/|\partial_\theta\langle M\rangle|^2$ come from, in estimation theory?

1 vote
1 answer
55 views

High logical error rates when implementing Lattice Surgery with Stim

2 votes
1 answer
141 views

Practical implementation of Shor and other factoring algorithms

3 votes
2 answers
61 views

Generalizing error propagation formula to multi-parameters

5 votes
0 answers
46 views

Can we beat Grover for derangement problems?

2 votes
1 answer
57 views

Fourier transform of the product of two wave functions

0 votes
1 answer
20 views

Fault tolerance of turning off a stabilizer measurement for later rounds of error correction?

3 votes
1 answer
105 views

How does quantum teleportation not lose information?

3 votes
1 answer
62 views

What are the main motivations for pursuing CSS codes over general non-CSS codes?

0 votes
1 answer
27 views

Surface code with measurement errors

0 votes
0 answers
17 views

Can we somehow relate quantum volume with the total number of gates present in a circuit which the machine can succesfully run without large errors

0 votes
1 answer
24 views

How to find a set of independent logical operators for a stabilizer code with Stim

3 votes
1 answer
108 views

How to perform amplitude amplification when the initial amplitude of aiming state is unknown

3 votes
1 answer
118 views

how to construct a ((7,2,3)) code and verify its properties

1 vote
1 answer
34 views

Implement parity check gadget using stim

1 vote
0 answers
19 views

Complexity of controlled-$U^j$ operations in QPE applied to Hamiltonian simulation

3 votes
0 answers
42 views

How to test matrix Hamiltonians for CPT symmetry

3 votes
0 answers
50 views
+50

Almost perfect quantum encryption of a mixed state using only $n + O(\log(n) +\log(\frac{1}{\epsilon}))$ shared bits

0 votes
0 answers
13 views

Computational basis absolute value coefficient of stabilizer state in STIM [duplicate]

1 vote
1 answer
40 views

Why are qubits initialized to $|0\rangle$ in parametrized quantum circuits?

3 votes
1 answer
53 views

In context of stabilizer codes, are logical gates and Pauli operators the same?

4 votes
1 answer
212 views

How do magic states circumvent the Eastin-Knill theorem?

3 votes
1 answer
261 views

How to simulate low-rank hamiltonian?

1 vote
0 answers
46 views

State tomography in Qiskit on a subset of qubits of real QPU

0 votes
0 answers
24 views

Calibrating qubits using Qiskit Pulse with Qiskit 1.0

1 vote
1 answer
35 views

Approximate decomposition of general $n$-qubit unitary to universal gate set

1 vote
1 answer
59 views

Proability of measuing a qubit in a two qubit system without having a perpendicular basis

4 votes
1 answer
60 views

What is an example of a problem that we strongly suspect lies in NP $\cap$ co-NP but not in BQP?

0 votes
0 answers
34 views

Proof that if W is the image of a Unitary operator with an $n^O(1)$ size quantum circuit, then $R_W$ has an $n^O(1)$ circuit as well


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