Hottest Questions This Month

10

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2

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908

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Is swap gate equivalent to just exchanging the wire of the two qubits?

quantum-gate

answered Jun 14 at 19:39 LambdaBeta 173

6

votes

2

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189

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Grover algorithm for a database search: where is the quantum advantage?

modified Jun 4 at 19:11 glS 5,205

2

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2

answers

438

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How to compute the inverse of an operation in Q#?

programming q#

answered 2 days ago Chris Granade 203

5

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3

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305

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Why is the application of an oracle function not a measurement?

algorithm measurement grovers-algorithm

modified Jun 3 at 11:35 glS 5,205

3

votes

1

answer

787

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Can someone walk us through Nielsen's proof on a circuit for quantum teleportation?

circuit-construction

modified May 27 at 20:39 Glorfindel 267

7

votes

2

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118

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How to program a controlled Hadamard-Hadamard gate?

programming circuit-construction qiskit

answered Jun 14 at 13:16 James Wootton 7,271

6

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1

answer

137

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Question on state distinguishability

quantum-state

modified Jun 10 at 19:08 Danylo Y 1,295

3

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3

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100

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How are orthogonal sets of pure states arranged in state space?

mathematics bloch-sphere state-space-geometry

modified Jun 6 at 18:06 Danylo Y 1,295

5

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2

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126

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Transform matrix into a combination of simple quantum gates

quantum-gate qiskit gate-synthesis

modified May 26 at 14:54 Arthur-1 126

7

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2

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166

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+100

Clarification of the “Calculations” section of the (HHL09) paper

algorithm hhl-algorithm

modified 2 days ago Sanchayan Dutta 7,836

2

votes

2

answers

265

views

What happens when an operator is applied only to some bits of a mixed state?

quantum-state entanglement

modified May 29 at 9:13 mike_dole_z3 13

6

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1

answer

200

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Grover's diffusion on subset of input space

algorithm grovers-algorithm

modified Jun 9 at 8:14 Sanchayan Dutta 7,836

3

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3

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152

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How to quickly calculate the custom U3 gate parameters $\theta, \phi$ and $\lambda$ for any unitary?

programming qiskit resource-request ibm-q-experience

modified Jun 4 at 15:19 Sanchayan Dutta 7,836

6

votes

1

answer

240

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Defining qubit operator from scratch

programming qiskit chemistry

modified Jun 3 at 15:02 Sanchayan Dutta 7,836

2

votes

1

answer

252

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Implement a Hamiltonian in O(n) - exercise question

algorithm hamiltonian-simulation

modified May 28 at 14:11 Sanchayan Dutta 7,836

4

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1

answer

222

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Understanding a quantum algorithm to estimate inner products

algorithm quantum-state mathematics measurement

modified Jun 5 at 10:47 glS 5,205

4

votes

2

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63

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Complex number in the representation of a qubit

quantum-state

answered Jun 7 at 1:23 Ruvi Lecamwasam 176

7

votes

2

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80

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Quantum channel representation of projective measurement

measurement nielsen-and-chuang quantum-channel projection-operator

modified Jun 13 at 17:29 glS 5,205

2

votes

1

answer

155

views

Circuit construction and Dirac notation of the following operation

quantum-gate quantum-state circuit-construction notation

modified May 25 at 17:00 Sanchayan Dutta 7,836

4

votes

2

answers

113

views

Is there any online Bloch sphere simulator?

resource-request simulation bloch-sphere

modified May 23 at 14:08 glS 5,205

3

votes

2

answers

117

views

Writing the notation when gates act on non successive registers

quantum-gate quantum-state notation tensor-product

modified May 28 at 17:36 Nelimee 2,015

8

votes

1

answer

75

views

Is there a general method of expressing optimization problem as a Hamiltonian?

adiabatic-model optimization

modified Jun 11 at 15:45 bRost03 282

6

votes

2

answers

116

views

How to interpret $-\rvert1\rangle \otimes \rvert1\rangle = -\rvert11\rangle$?

quantum-state physical-qubit tensor-product

modified Jun 1 at 15:09 glS 5,205

3

votes

2

answers

67

views

Expressing CNOT in the eigenbasis of $X$ (Preskill lecture notes eq. 7.6)

quantum-gate pauli-gates

modified Jun 5 at 10:46 glS 5,205

4

votes

1

answer

101

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Understanding the classification of quantum states based on partial transposition: representations of the bipartite density matrix

entanglement density-matrix

modified yesterday Sanchayan Dutta 7,836

5

votes

1

answer

122

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What are the basics needed to learn quantum computing?

resource-request

modified May 25 at 18:26 magic_man 144

2

votes

1

answer

88

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How to construct a CCY gate in Qiskit

quantum-gate qiskit

modified Jun 5 at 18:11 Jeff 30

3

votes

1

answer

74

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Weeding out qubit states with leftmost qubit as 1

quantum-state ibm-q-experience projection-operator

modified Jun 11 at 8:51 Sanchayan Dutta 7,836

6

votes

1

answer

57

views

How to decompose a controlled unitary $C(U)$ operation where $U$ is a 2-qubit gate?

quantum-gate gate-synthesis

answered Jun 3 at 19:41 AHusain 2,380

3

votes

1

answer

73

views

Why does a quantum circuit consist of simple quantum gates which act on at most a fixed number of qubits?

quantum-gate

modified May 21 at 18:03 Victory Omole 510

1

vote

1

answer

85

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Quantum secret Sharing using GHZ state paper

quantum-state entanglement measurement

modified Jun 14 at 7:53 Upstart 392

5

votes

1

answer

40

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Clarification of a procedure to compute the product of the exponential of two matrices

mathematics hamiltonian-simulation

modified Jun 6 at 10:51 glS 5,205

5

votes

1

answer

61

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Implementation of Grover's Algorithm (minimum spanning tree)

algorithm grovers-algorithm

modified Jun 7 at 14:11 Sanchayan Dutta 7,836

4

votes

1

answer

60

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What is the HOG test and how would it help proving quantum supremacy?

mathematics quantum-advantage boson-sampling

modified May 24 at 13:44 Mark S 1,020

5

votes

1

answer

55

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How to tell if the ground states of two Hamiltonians are solutions of the same optimization problem?

quantum-state adiabatic-model optimization

modified Jun 12 at 18:16 Niel de Beaudrap 6,775

7

votes

1

answer

42

views

How to calculate the distance of stabilizer code?

error-correction stabilizer-code

answered Jun 4 at 8:02 DaftWullie 18k

5

votes

1

answer

67

views

Physical qubit of optical quantum computer

physical-realization architecture physical-qubit optical-quantum-computing

answered May 30 at 21:15 Josh Izaac 96

5

votes

1

answer

65

views

How to calculate the fidelity of a certain gate of a IBMQ device in Qiskit using randomized benchmarking/tomography?

programming qiskit fidelity tomography

modified 32 mins ago James Wootton 7,271

6

votes

1

answer

79

views

What is the definition of Bell state on a n-qubit system?

entanglement resource-request error-correction terminology surface-code

modified Jun 10 at 13:50 bRost03 282

1

vote

3

answers

61

views

Controlled Z gate acting on 3 qubits in matrix form

quantum-gate matrix-representation

answered 3 hours ago DaftWullie 18k

3

votes

1

answer

47

views

About the Qiskit draw function

programming qiskit

modified Jun 9 at 8:21 Sanchayan Dutta 7,836

1

vote

1

answer

98

views

Which is the correct depiction of a qubit before it collapses?

quantum-state notation

modified May 29 at 8:48 glS 5,205

3

votes

2

answers

59

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Amplitude suppression

amplitude-amplification

modified Jun 13 at 7:03 DaftWullie 18k

3

votes

1

answer

56

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What “states” can a qubit have if it doesn't have values?

quantum-state physical-qubit

modified Jun 4 at 10:39 glS 5,205

5

votes

1

answer

43

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Equivalent determinant condition for Peres-Horodecki criteria

entanglement mathematics density-matrix matrix-representation

modified yesterday DaftWullie 18k

2

votes

1

answer

51

views

Why should we use inverse QFT instead of QFT in Shor's algorithm?

algorithm shors-algorithm quantum-fourier-transform

modified Jun 11 at 0:50 João Bravo 113

1

vote

2

answers

83

views

How do the credit points work in IBM quantum experience?

ibm-q-experience

answered Jun 5 at 7:43 Daniel Vainshtein 210

4

votes

1

answer

50

views

Structural Physical Approximation of Partial Transpose

quantum-information entanglement mathematics quantum-operation

modified May 22 at 7:33 DaftWullie 18k

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