Hottest Questions This Month

7

votes

2

answers

329

views

Could the Hadamard gate have been constructed differently with similar characteristics?

modified Oct 14 at 4:20 Sanchayan Dutta 8,466

5

votes

3

answers

145

views

Quantum operation that always produces output orthogonal to input

quantum-operation unitarity

modified Oct 9 at 6:56 Sanchayan Dutta 8,466

5

votes

2

answers

85

views

How and why does swap test works?

algorithm quantum-gate quantum-state

modified 2 days ago Sanchayan Dutta 8,466

7

votes

2

answers

239

views

Understanding Google's “Quantum supremacy using a programmable superconducting processor” (Part 1): choice of gate set

quantum-gate superconducting-quantum-computing quantum-advantage random-quantum-circuit google-sycamore

modified Oct 2 at 19:23 Mark S 1,479

5

votes

1

answer

131

views

Can quantum computing contribute to the development of artificial intelligence?

machine-learning applications artificial-intelligence

modified Oct 9 at 6:41 Sanchayan Dutta 8,466

3

votes

1

answer

96

views

What is a “barrier” in Qiskit circuits?

qiskit circuit-construction ibm-q-experience

modified Oct 9 at 6:34 Sanchayan Dutta 8,466

5

votes

2

answers

73

views

Is there an algorithm for determining if a given vector is separable or entangled?

mathematics tensor-product

modified Oct 9 at 6:43 Sanchayan Dutta 8,466

4

votes

2

answers

245

views

Quantum Supremacy: Some questions on cross-entropy benchmarking

experiment entropy quantum-advantage google-sycamore

modified 4 hours ago Björn Smedman 24

2

votes

1

answer

172

views

Understanding Google's “Quantum supremacy using a programmable superconducting processor” (Part 3): sampling

quantum-gate superconducting-quantum-computing quantum-advantage random-quantum-circuit google-sycamore

modified Sep 30 at 1:42 Sanchayan Dutta 8,466

2

votes

3

answers

128

views

Does a quantum computer have a clock signal and if yes how big is it?

classical-computing

answered Oct 10 at 20:59 sandualuclopotaru 56

4

votes

1

answer

206

views

Understanding Google's “Quantum supremacy using a programmable superconducting processor” (Part 2): simplifiable and intractable tilings

quantum-gate superconducting-quantum-computing quantum-advantage random-quantum-circuit google-sycamore

modified Oct 5 at 15:41 Mark S 1,479

4

votes

2

answers

89

views

Input and output qubit notation in quantum gates

quantum-gate quantum-state notation

modified Oct 14 at 21:18 ChainedSymmetry 633

-1

votes

4

answers

109

views

How many combinations can 'n' qubits have?

quantum-state superposition

modified Sep 29 at 16:45 LiNKeR 112

3

votes

1

answer

101

views

Notation question: How would one read $|0\rangle (|0\rangle+|0\rangle)$?

notation

modified Sep 30 at 16:09 ChainedSymmetry 633

2

votes

2

answers

73

views

How to decompose a unitary transform into two-level unitary matrices?

algorithm quantum-gate

answered yesterday glS 6,237

5

votes

1

answer

90

views

What does W stand for in the W entangled state?

quantum-state entanglement resource-request history

modified yesterday glS 6,237

3

votes

3

answers

84

views

How to plot custom gate labels in Qiskit?

programming qiskit

answered Sep 30 at 12:09 Matthew Treinish 41

3

votes

2

answers

63

views

How do I compute the Relative Entropy between pure and mixed states?

quantum-information density-matrix entropy

modified Oct 6 at 4:08 glS 6,237

2

votes

2

answers

99

views

How to unpickle a Result object returned by an IBMQ experiment?

programming qiskit ibm-q-experience

modified Sep 29 at 9:08 Sanchayan Dutta 8,466

2

votes

2

answers

75

views

How to prepare a specific initial state of three qubits?

programming qiskit cirq

modified 2 days ago Sanchayan Dutta 8,466

1

vote

3

answers

158

views

Can everything in QM be described with degrees instead of matrices and vectors?

quantum-gate quantum-state quantum-information hadamard

answered Oct 10 at 16:43 glS 6,237

3

votes

2

answers

57

views

Probability of equal outcomes measuring a Bell state in the directions $\vec{n}_1,\vec{n}_2$

entanglement measurement bloch-sphere

modified Oct 16 at 14:12 glS 6,237

7

votes

1

answer

117

views

Do pure states lie on a hypersphere in the Bloch representation?

quantum-state bloch-sphere state-space-geometry

modified Oct 10 at 10:36 glS 6,237

2

votes

1

answer

89

views

Understanding the action of operators on vectors in tensor product spaces

mathematics tensor-product

modified Oct 9 at 6:47 Sanchayan Dutta 8,466

3

votes

1

answer

95

views

How to prepare an initial state for variational quantum algorithms?

algorithm quantum-state

answered Oct 10 at 18:09 C. Kang 300

1

vote

1

answer

95

views

Transforming the first Bell state into the other Bell states

quantum-gate quantum-state bell-basis

modified 2 days ago Sanchayan Dutta 8,466

1

vote

3

answers

89

views

How many classical registers are there on (IBM) quantum computers?

programming qiskit ibm-q-experience

answered Sep 29 at 21:08 Ali Javadi 658

3

votes

2

answers

40

views

Prove that the partial trace is equivalent to measuring and discarding

measurement density-matrix partial-trace

answered Oct 16 at 14:28 glS 6,237

4

votes

2

answers

50

views

Why does a controlled gate not constitute a measurement?

quantum-gate measurement

modified Oct 19 at 19:43 ChainedSymmetry 633

3

votes

1

answer

60

views

Applications of quantum computing for science popularization

applications

modified Oct 8 at 21:44 Sanchayan Dutta 8,466

4

votes

1

answer

57

views

Developing quantum circuits for specific quantum chemistry configurations

circuit-construction chemistry

modified 2 days ago Sanchayan Dutta 8,466

4

votes

1

answer

56

views

Matrix Index and multiplication rules for Hermitian Pauli group products

mathematics error-correction pauli-gates

answered 2 days ago DaftWullie 21.5k

4

votes

1

answer

55

views

How to check if a two-qubit gate is entangling?

quantum-gate entanglement mathematics

answered 2 days ago Sanchayan Dutta 8,466

4

votes

2

answers

53

views

Physical Interpretation of Pauli Matrices as Polarization Check

quantum-gate quantum-state measurement pauli-gates photonics

modified Oct 12 at 17:19 Felix Huber 91

-3

votes

1

answer

107

views

Exploring quantum computing with Qiskit [closed]

qiskit

modified Oct 15 at 13:20 Sanchayan Dutta 8,466

7

votes

1

answer

82

views

Are 20 repetitions of Sycamore's one- and 2-qubit gates sufficient to produce a uniformly random state?

quantum-advantage random-quantum-circuit google-sycamore

answered Oct 14 at 3:02 Mark S 1,479

4

votes

1

answer

80

views

Proving $\langle j_2|\langle j_1| U(|0\rangle\!\langle0|\otimes\rho)U^\dagger|j_2\rangle|j_1\rangle =\operatorname{Tr}(M_j\rho)$

mathematics density-matrix

modified 19 hours ago Mithrandir24601♦ 2,807

2

votes

1

answer

60

views

Why can we forget about the ancilla bit in Grover's algorithm?

algorithm quantum-information grovers-algorithm

modified Oct 14 at 4:18 Sanchayan Dutta 8,466

4

votes

1

answer

59

views

Resources in Spanish to start learning quantum computing and quantum programming (Qiskit)

programming qiskit resource-request

modified Oct 16 at 15:22 Sanchayan Dutta 8,466

4

votes

1

answer

96

views

Location of “bad” qubits on Sycamore

architecture google-sycamore

answered Oct 6 at 2:42 Pablo LiManni 108

1

vote

1

answer

94

views

Quantum computer vs. supercomputer performance [on hold]

classical-computing performance

modified Oct 19 at 20:51 Bob Walance 17

3

votes

1

answer

43

views

What's the difference between observing in a given direction and operating in that same direction?

quantum-gate measurement physical-qubit quantum-operation

answered Oct 16 at 11:00 glS 6,237

3

votes

0

answers

116

views

Is it possible to run a general implementation Shor's algorithm on a real IBM quantum computer at least for N = 15?

qiskit ibm-q-experience shors-algorithm

modified Sep 29 at 19:39 WaSon 16

2

votes

1

answer

42

views

How to design a measurement that distinguishes the following pair of two-qubit states?

quantum-state measurement

modified Oct 9 at 6:58 Sanchayan Dutta 8,466

1

vote

3

answers

67

views

Ideas for school-level project on quantum computing

algorithm research

answered Oct 16 at 6:35 Bob Walance 17

4

votes

1

answer

52

views

How to split a 2-local unitary operator through singular value decomposition?

mathematics tensor-networks

modified Oct 16 at 12:19 Dyon J Don Kiwi van Vreumingen 399

1

vote

1

answer

65

views

Trace of Hermitian Operator and Operator Function

quantum-information mathematics measurement density-matrix

modified Oct 9 at 18:36 Sanchayan Dutta 8,466

2

votes

1

answer

39

views

Analysis of the second Hadamard in the Detusch-Josza Algorithm

algorithm deutsch-jozsa-algorithm hadamard

modified Oct 4 at 1:10 glS 6,237

Top Questions

Looking for more? Browse the complete list of questions, or popular tags. Help us answer unanswered questions.