Hottest Questions This Month

7

votes

2

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977

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Changing one qubit causes changes in another independent qubit on ibmqx2 in IBM Q Experience

ibm-q-experience experiment

modified Dec 28 '19 at 17:42 Martin Vesely 1,585

5

votes

2

answers

149

views

Is there anything practical that can be done with a single qubit?

quantum-state physical-qubit

answered 2 days ago Greenstick 419

5

votes

2

answers

543

views

Is a qubit always in superposition?

quantum-state superposition

answered Jan 9 at 0:24 glS 8,887

4

votes

2

answers

121

views

What unitary gate produces these quantum states from the computational basis?

quantum-gate quantum-state unitarity

modified Jan 10 at 9:44 Martin Vesely 1,585

3

votes

1

answer

127

views

What does it mean “less than identity” in the operator sum representation?

quantum-operation operator-sum

modified Jan 21 at 10:11 glS 8,887

4

votes

3

answers

70

views

Why do purifications only differ by a local unitary?

entanglement density-matrix

answered Jan 3 at 18:02 glS 8,887

4

votes

3

answers

170

views

Are there Bell-like violations that can be observed without collecting statistics?

quantum-information resource-request bell-experiment non-locality

modified Jan 21 at 14:05 kludg 1,709

4

votes

1

answer

200

views

What kind of errors does the master equation in the Lindblad form describe, continuous errors or discrete errors?

error-correction nielsen-and-chuang noise

modified Jan 10 at 14:12 Martin Vesely 1,585

5

votes

1

answer

114

views

Can a Toffoli gate be implemented using Fredkin gates?

circuit-construction universal-gates

modified Jan 9 at 0:27 glS 8,887

-1

votes

1

answer

196

views

Why is a Hadamard gate unitary?

quantum-state unitarity hadamard

modified Jan 4 at 21:59 Niel de Beaudrap 8,294

4

votes

2

answers

87

views

How to implement the CCH gate in quantum computers available in clouds?

quantum-gate qiskit circuit-construction ibm-q-experience

modified Jan 10 at 15:27 glS 8,887

1

vote

2

answers

141

views

How can I find the $\theta$ and $\phi$ values of a qubit on the Bloch sphere?

quantum-state nielsen-and-chuang bloch-sphere

answered Jan 9 at 11:21 Martin Vesely 1,585

4

votes

1

answer

107

views

Why is the size of the top register for Shor's algorithm chosen as it is?

shors-algorithm

answered Jan 21 at 19:25 John Watrous 2,483

5

votes

1

answer

137

views

Uncomputation in quantum implementation of a classical algorithm

circuit-construction nielsen-and-chuang

modified Jan 4 at 19:51 kludg 1,709

2

votes

2

answers

119

views

How to identify entanglement in a given pure state?

entanglement

modified Jan 10 at 16:14 glS 8,887

4

votes

3

answers

56

views

Logical qubit initialization for the surface code

error-correction surface-code

modified Jan 9 at 1:35 Craig Gidney 7,591

1

vote

3

answers

146

views

How to realize this quantum error correction circuit on real hardware?

qiskit error-correction

answered Jan 13 at 18:37 Martin Vesely 1,585

3

votes

1

answer

77

views

Optimizing over quantum channels

quantum-channel optimization

modified Jan 16 at 17:01 John Watrous 2,483

2

votes

1

answer

98

views

Non-unitary matrix decomposition as a sum of unitary matrices

mathematics matrix-representation

modified Jan 15 at 14:37 Danylo Y 2,439

2

votes

2

answers

93

views

What is the property of any entangled pair of qubits?

entanglement measurement bell-basis

modified Jan 20 at 10:10 JSdJ 609

1

vote

2

answers

91

views

Can a qubit be in the inside of the Bloch Sphere?

quantum-state bloch-sphere

modified Jan 16 at 12:10 glS 8,887

1

vote

1

answer

149

views

How to implement if statement based on measurement results in qiskit?

qiskit error-correction

answered Jan 2 at 10:28 dlyongemallo 231

3

votes

1

answer

87

views

Qiskit in Julia language?

qiskit

modified Jan 1 at 14:32 Nick Decroos 124

6

votes

1

answer

110

views

Decomposing a $(w+1)$-qubit permutation gate into $w$-qubit permutation gates, SWAPs and NOTs

quantum-gate circuit-construction

answered Jan 7 at 17:24 AHusain 3,158

3

votes

1

answer

87

views

Where are the physical gates in the Google processor?

quantum-gate physical-realization google-sycamore

modified Jan 22 at 13:26 Mark S 2,685

6

votes

1

answer

49

views

Could quantum computers be useful for sending encrypted information over a classical channel?

algorithm cryptography communication-complexity

modified Jan 3 at 5:11 tparker 824

4

votes

2

answers

61

views

Why do multi-bit hadamards expands to what they do?

deutsch-jozsa-algorithm hadamard

modified Jan 10 at 9:30 Mithrandir24601♦ 2,981

-3

votes

2

answers

127

views

Building a DIY quantum computer - how to reduce a noise?

physical-realization physical-qubit noise

modified Jan 19 at 7:29 Martin Vesely 1,585

5

votes

1

answer

58

views

What is the practical interest of superdense coding?

quantum-information communication superdense-coding

modified Jan 6 at 22:43 glS 8,887

3

votes

1

answer

93

views

How to invoke a C# method inside a Q# operation?

programming q#

answered Jan 11 at 20:22 Mariia Mykhailova 4,138

0

votes

1

answer

69

views

What is the |+⟩ and |-⟩ state?

quantum-state hadamard

modified Jan 16 at 11:35 luigi 41

2

votes

1

answer

109

views

Why is implementation of controlled Hadamard on IBM Q so complex?

quantum-gate circuit-construction ibm-q-experience hadamard

modified Jan 11 at 13:43 met927 1,457

-1

votes

2

answers

51

views

How to find eigenvalues and eigenvector for a quantum gate? [closed]

quantum-gate quantum-state

modified Jan 19 at 0:06 Martin Vesely 1,585

3

votes

2

answers

132

views

Cannot replicate results in article on pricing financial derivatives on IBM Q

ibm-q-experience quantum-fourier-transform phase-estimation quantum-computing-for-finance

modified Jan 13 at 22:25 Davit Khachatryan 231

2

votes

2

answers

79

views

Is it possible to create a Q# operation with optional parameters?

programming q#

answered Jan 14 at 21:02 Chris Granade 473

3

votes

1

answer

78

views

Understanding surface code diagrams

error-correction surface-code

answered Jan 8 at 8:11 DaftWullie 24.7k

1

vote

1

answer

78

views

Quantum Principal Component analysis by Seth Lloyd

mathematics quantum-operation tensor-product

modified Jan 17 at 13:18 kludg 1,709

1

vote

2

answers

58

views

IBM quantum computers gate delay values

quantum-gate ibm-q-experience decoherence

answered Jan 22 at 15:36 Yael Ben-Haim 41

5

votes

1

answer

45

views

What is the difference between the “Fubini-Study distances” $\arccos|\langle\psi|\phi\rangle|$ and $\sqrt{1-|\langle\psi|\phi\rangle|}$?

fidelity state-space-geometry

modified 21 hours ago Chris Ferrie 302

4

votes

1

answer

95

views

What is the state of the art on Quantum Random Access Memories? [duplicate]

ibm-q-experience physical-realization architecture research quantum-memory

modified Jan 9 at 2:22 Sanchayan Dutta 12.8k

-3

votes

1

answer

95

views

what are the angles 𝜃, and ϕ values of the following quantum state? [duplicate]

quantum-state quantum-information nielsen-and-chuang bloch-sphere

modified Jan 6 at 12:27 Ba. Taj 150

3

votes

1

answer

57

views

Does the Lieb-Robinson bound constrain the speed of entanglement information transmission?

quantum-information bb84

modified Jan 9 at 2:16 Sanchayan Dutta 12.8k

2

votes

2

answers

120

views

What is the best way to get into and learn quantum computing for a 14 year old?

resource-request

answered Jan 20 at 4:55 Steven Sagona 368

4

votes

2

answers

54

views

Diagrammatic Quantum Reasoning: Proving the loop equation using yanking equations

mathematics zx-calculus

answered Jan 4 at 14:35 Mahathi Vempati 1,689

2

votes

1

answer

42

views

Is qiskit_backend_monitor magic function depricated?

qiskit

answered Jan 8 at 0:32 Matthew Treinish 161

1

vote

1

answer

53

views

What is the outcome of this circuit?

quantum-gate

modified Jan 13 at 18:07 Davit Khachatryan 231

2

votes

4

answers

52

views

Implementing four oracles for the Deutsch Algorithm (preferably on IBM Q Experience)

ibm-q-experience deutsch-jozsa-algorithm

modified Jan 18 at 8:40 Martin Vesely 1,585

3

votes

2

answers

66

views

Problem involving entanglement swapping

entanglement measurement teleportation

modified Jan 11 at 10:47 Danylo Y 2,439

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