Hottest Questions This Month

18

votes

4

answers

2k

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Why can't there be an error correcting code with fewer than 5 qubits?

error-correction

modified Dec 1 at 16:14 Niel de Beaudrap 5,346

5

votes

3

answers

133

views

Density matrix after measurement on density matrix

answered Dec 1 at 11:58 DaftWullie 11.6k

3

votes

2

answers

188

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Are projective measurement bases always orthonormal?

measurement

answered Dec 3 at 19:04 glS 3,546

5

votes

2

answers

225

views

How to describe, or encode, the input vector x of Quantum Fourier Transform?

algorithm quantum-fourier-transform

modified Nov 20 at 14:01 Blue♦ 5,645

1

vote

2

answers

553

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Measuring but not looking at the result

measurement density-matrix decoherence

modified Dec 14 at 12:02 Blue♦ 5,645

6

votes

2

answers

117

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Quantum Supremacy: How do we know that a better classical algorithm doesn't exist?

algorithm classical-computing quantum-advantage

modified Nov 20 at 9:50 Norbert Schuch 1,213

8

votes

1

answer

139

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Isomorphism between the Clifford group and the quaternions

clifford-group

modified Dec 12 at 10:10 Carucel 115

5

votes

1

answer

181

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Problem with the mathematical formulation of “qubitization”

mathematics hamiltonian-simulation notation

modified Dec 11 at 13:33 Nelimee 1,270

2

votes

1

answer

206

views

Is it possible to expand/merge different circuits?

programming qiskit ibm-q-experience

modified Dec 10 at 4:18 Blue♦ 5,645

3

votes

1

answer

130

views

Quantum Zeno Machines

complexity-theory quantum-turing-machine

modified Nov 29 at 15:45 meowzz 1,242

4

votes

2

answers

73

views

Grover's algorithm with W-state

algorithm entanglement grovers-algorithm

modified 2 days ago tigerjack89 205

3

votes

2

answers

68

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Implementing gate with two parameters using Qiskit in Python

quantum-gate programming qiskit hhl-algorithm

modified Nov 26 at 18:33 Blue♦ 5,645

3

votes

2

answers

64

views

Time-bin encoding qudits

resource-request qudit photonics

answered Dec 11 at 10:26 glS 3,546

3

votes

1

answer

98

views

Total mutual information of a quantum system

quantum-information measurement density-matrix entropy

modified Dec 14 at 5:52 Blue♦ 5,645

4

votes

1

answer

71

views

Construction of ${R_n(\theta)}$ using only the Hadamard and ${\pi/8}$ gates

quantum-gate nielsen-and-chuang

modified Dec 4 at 17:24 Blue♦ 5,645

4

votes

1

answer

91

views

How to analyze highly entangled quantum circuits?

algorithm entanglement circuit-model phase-estimation

modified Nov 25 at 11:00 glS 3,546

4

votes

2

answers

69

views

How to get all combinations of given input?

algorithm circuit-model

answered Dec 7 at 19:46 Craig Gidney 3,342

4

votes

1

answer

67

views

Determining whether $P(ab|xy)$ factorizes in Bell experiments

quantum-information mathematics quantum-correlation non-locality

answered Nov 22 at 8:47 DaftWullie 11.6k

2

votes

1

answer

85

views

An algorithm with the Hadamard operator

algorithm programming q#

modified Nov 28 at 4:13 Blue♦ 5,645

2

votes

1

answer

108

views

Notation for two entangled registers

entanglement notation

modified Dec 10 at 19:20 Sideshow Bob 113

1

vote

2

answers

61

views

A question about notation for quantum states

quantum-state notation

modified Dec 6 at 7:54 Blue♦ 5,645

4

votes

1

answer

46

views

Implementation of inverse QFT?

algorithm circuit-model quantum-fourier-transform

modified Dec 6 at 8:13 Blue♦ 5,645

2

votes

1

answer

59

views

Projection operators and positive operators

mathematics projection-operator

answered Nov 21 at 7:49 DaftWullie 11.6k

1

vote

1

answer

59

views

Depolarizing channel operator sum representation

quantum-information quantum-channel

modified yesterday Norbert Schuch 1,213

6

votes

1

answer

95

views

Why is this implementation of the order finding algorithm not working?

algorithm shors-algorithm cirq

modified Dec 13 at 16:08 Blue♦ 5,645

2

votes

1

answer

92

views

Are there emulators for quantum networks?

resource-request simulation quantum-networks emulation

modified yesterday meowzz 1,242

4

votes

1

answer

55

views

Magic State Distillation Understanding Check

fault-tolerance surface-code

modified Nov 22 at 18:24 Craig Gidney 3,342

1

vote

1

answer

68

views

How to measure in the standard basis?

qubit-state measurement

modified Nov 21 at 13:53 DaftWullie 11.6k

4

votes

1

answer

67

views

How can we be sure that for every $A$, $A^\dagger A$ has a positive square root?

mathematics matrix-representation nielsen-and-chuang

modified Dec 2 at 13:50 glS 3,546

3

votes

1

answer

52

views

Confusion on the definition of the phase-damping channel

error-correction quantum-channel

answered Nov 27 at 0:58 AHusain 1,352

2

votes

2

answers

85

views

Non-layperson explanation of why a qubit is more useful than a bit?

qubit qubit-state resource-request

modified Dec 6 at 8:22 Blue♦ 5,645

3

votes

2

answers

51

views

Shannon entropy is least when Measurement basis = Mixture basis

qubit quantum-information entropy

modified 6 hours ago Blue♦ 5,645

4

votes

1

answer

47

views

Expected repetitions of the quantum part of Shor's algorithm

algorithm shors-algorithm

modified Dec 13 at 23:02 Craig Gidney 3,342

3

votes

1

answer

76

views

Is geometric algebra/calculus used in quantum computing?

mathematics

modified Nov 23 at 4:18 Blue♦ 5,645

3

votes

1

answer

59

views

Can vectorization lead to mixed states?

quantum-information

modified Dec 3 at 7:49 Blue♦ 5,645

2

votes

1

answer

72

views

A quantum circuit with entanglement with Eve

quantum-gate entanglement quantum-information

answered Nov 28 at 8:10 DaftWullie 11.6k

2

votes

0

answers

117

views

Eigenvalues of CPT operator

resource-request cpt-symmetry

modified Dec 14 at 6:15 Blue♦ 5,645

5

votes

1

answer

43

views

Proof on approximating adiabatic evolution by quantum circuit

adiabatic-model

modified Dec 10 at 9:47 DaftWullie 11.6k

7

votes

0

answers

90

views

Quantum algorithms for problems outside NP

algorithm speedup complexity-theory

modified Dec 7 at 22:20 Daniel Mahler 136

2

votes

1

answer

70

views

List of known circuits and their expected output

resource-request simulation circuit-model

modified Nov 20 at 14:48 nikojpapa 304

3

votes

2

answers

54

views

How to fix? 'E1101:Instance of 'QuantumCircuit' has no 'h' member' and 'E1101:Instance of 'QuantumCircuit' has no 'cx' member'

programming qiskit

answered Dec 15 at 10:59 Norrius 292

4

votes

1

answer

69

views

How to find parameters for circuit decomposition of Hamiltonian simulation of any matrix $A$?

algorithm hhl-algorithm hamiltonian-simulation

modified Nov 26 at 8:14 DaftWullie 11.6k

4

votes

1

answer

82

views

Unitary gate(s) from product of exponent

quantum-gate simulation unitarity

modified Nov 30 at 11:52 nippon 471

1

vote

1

answer

47

views

Shared entanglement to copy orthogonal states

entanglement quantum-information cloning

modified Nov 27 at 1:54 Blue♦ 5,645

3

votes

1

answer

28

views

Are the order finding and period finding algorithms the same thing?

algorithm

modified Dec 5 at 10:22 DaftWullie 11.6k

2

votes

1

answer

59

views

Graph state and maximally entangled state

entanglement qudit graph-states

answered Nov 23 at 9:39 DaftWullie 11.6k

4

votes

1

answer

53

views

Stabilizer for quantum error correction code

error-correction stabilizer-state

modified Nov 20 at 8:32 Niel de Beaudrap 5,346

0

votes

2

answers

85

views

How to prepare a superposed states of odd integers from $1$ to $\sqrt{N}$?

algorithm superposition

answered Dec 4 at 1:07 Bruno Chagas 9

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