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Am I doing anything wrong when trying to calculate the expectation value in Qiskit on the real hardware?

qiskit

asked 2 hours ago physavage 131

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1

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14

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Randomness using simple parallel Hadamard circuit

answered 4 hours ago Craig Gidney 9,147

1

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1

answer

59

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How does the graphical notation used to denote doubly-controlled gates work?

quantum-gate matrix-representation notation

modified 4 hours ago M. Stern 1,759

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12

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How to construct quantum circuit to count number of 0-qubits and 1-qubits

circuit-construction

asked 7 hours ago Isomorphism 1

1

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1

answer

74

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Can quantum computing help to recover a lost private key?

programming

answered yesterday Jonathan Trousdale 1,786

1

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0

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16

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What is the pseudo threshold of a QECC using stabilizer formalism

quantum-information error-correction stabilizer-code terminology fault-tolerance

modified 5 hours ago El-Mo 119

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1

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33

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Is running a for loop faster on a quantum computer than a classical computer?

algorithm

answered yesterday Craig Gidney 9,147

0

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1

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35

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Confused regarding explanation of Schumachers compression in N&C

quantum-information nielsen-and-chuang quantum-channel

modified 11 hours ago glS 10.2k

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14

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Computing the expectation values of a Hamiltonian constructed from a cost functions in combinatorial optimization

algorithm optimization dynamics

modified 14 hours ago glS 10.2k

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1

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48

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Is the Hilbert-Schmidt probability simply zero that a generic rank-2 two-qubit (“pseudo-pure”) density matrix is separable?

quantum-state quantum-information entanglement density-matrix

modified 8 hours ago Paul B. Slater 631

1

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1

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41

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What can be inferred about the closeness of reduced qubit states from the closeness of the bipartite quantum state?

quantum-state quantum-information density-matrix fidelity partial-trace

modified yesterday Niraj Kumar 97

1

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2

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52

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Is there anything Quantikz can do that Tikz cannot do?

quantum-gate circuit-construction

modified yesterday user1271772 6,939

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3

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49

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Can you encode two values in a single qubit state, say its phase and orientation?

quantum-state

answered yesterday Aleksey Zhuravlev 25

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2

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44

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Find the Kraus operators of a combined amplitude and phase damping channel

error-correction quantum-channel operator-sum

answered yesterday glS 10.2k

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1

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95

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Operations needed for successful teleportation

teleportation

modified 2 days ago Upstart 976

1

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1

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54

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What extra functionality is available to an IBM Q Network member over a regular IBM Q Experience user

qiskit programming ibm-q-experience ibm

modified 6 hours ago glS 10.2k

1

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1

answer

45

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Quantum-Assisted Neural Network Training (Is my design reasonable?)

algorithm quantum-state machine-learning

modified yesterday Mridul 105

2

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1

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73

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How to implement Cx mod N unitary

algorithm qiskit programming circuit-construction shors-algorithm

modified yesterday glS 10.2k

1

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1

answer

70

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Why after transpiling a Qiskit circuit we obtain a different result?

qiskit programming ibm-q-experience quantum-fourier-transform initialization

answered yesterday Paula G 131

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1

answer

62

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How the simulator work?

quantum-gate quantum-state qiskit programming simulation

modified yesterday glS 10.2k

0

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1

answer

33

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How can I represent mixed states in Q#?

quantum-state programming q#

modified 6 hours ago glS 10.2k

2

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1

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73

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How to prepare a quantum circuit for $\frac{1}{\sqrt{3}}(|00\rangle+|01\rangle+|10\rangle)$ starting from $|00\rangle$

quantum-gate quantum-state circuit-construction entanglement

modified 16 hours ago glS 10.2k

1

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1

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28

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What is the representative matrix for a measurement in the Bell-state basis?

measurement bell-basis

modified 6 hours ago glS 10.2k

1

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1

answer

29

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Visualizing custom gates in Cirq

quantum-gate programming cirq

modified 6 hours ago glS 10.2k

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1

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29

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Question regarding part of the proof for the typical subspace theorem

quantum-information error-correction nielsen-and-chuang

modified 16 hours ago glS 10.2k

1

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1

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21

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Applying a gate to all line qubits without explicitly listing them in Cirq

quantum-gate programming circuit-construction cirq

modified 6 hours ago glS 10.2k

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1

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38

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Question About How Qiskit Reset Gate Affects Other Entangled Qubits

quantum-gate qiskit programming ibm-q-experience measurement

modified 6 hours ago glS 10.2k

4

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3

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78

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Can you transform a quantum program into an arrangement of slits?

programming

answered yesterday DaftWullie 30.6k

6

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3

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106

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How to implement a while loop in a quantum computer?

algorithm physical-realization

modified yesterday Fleeep 267

-1

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2

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77

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Nielsen and Chuang: Demonstration of equation 2.12

nielsen-and-chuang matrix-representation textbook-and-exercises

modified Jul 10 at 11:12 user12984287 502

2

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0

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35

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Recording Quantum Queries

quantum-information oracles

modified Jul 10 at 19:02 Pratyush Ranjan Tiwari 21

2

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3

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136

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What's the purpose of phases in quantum mechanics?

quantum-state

modified Jul 11 at 8:37 keisuke.akira 640

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41

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Feedback on Deutsch-Josza alg. homework prob. in Learning Quantum computation using Qiskit [closed]

qiskit

answered Jul 9 at 15:41 Lena 191

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1

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23

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Couldn't connect to IBMQ server: error during login: Expecting value: line 1 column 1 (char 0)?

qiskit

answered Jul 10 at 12:59 jyu00 31

4

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2

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72

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How to measure the sign of quantum amplitudes

quantum-state quantum-information measurement tomography

answered Jul 7 at 12:33 DaftWullie 30.6k

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2

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41

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Are there any resources of lists of attempts at non-probabilistic models of quantum mechanics, with debunking?

quantum-state resource-request

answered Jul 9 at 4:33 kludg 2,210

2

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1

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39

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Calcuate $\langle x | D | y \rangle$ for arbitrary $x,y \in \{0,1\}^n$

algorithm grovers-algorithm

modified Jul 8 at 19:59 user12984287 502

4

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1

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98

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Energy cost of quantum computation

cryptography shors-algorithm entropy

modified Jul 8 at 7:43 kludg 2,210

1

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1

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74

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Correct interpretation of a Quantum State

quantum-state

modified Jul 8 at 9:49 Jonathan Trousdale 1,786

2

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1

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246

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Quantum Circuit To Compute Any Inner Product

quantum-gate algorithm machine-learning neural-network

answered Jul 6 at 9:29 user12984287 502

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1

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116

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Are the skills learned for a degree in Computer Engineering helpful in learning Quantum Computing? [closed]

algorithm quantum-information entanglement

modified Jul 7 at 14:19 Mark S 3,227

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2

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49

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Is there a notion of “computational security” in quantum cryptography?

cryptography bb84

modified Jul 8 at 9:22 jgerrit 21

3

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1

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53

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Expectation value of an operator error: Composition is not defined over operators of different dimensions,

quantum-gate quantum-state qiskit programming

modified Jul 7 at 13:08 glS 10.2k

3

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1

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47

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Grover's Algorithm on a Database with more than 50% matching entries

quantum-gate algorithm grovers-algorithm

modified Jul 6 at 6:24 Martin Vesely 5,199

2

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1

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52

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How do you embed a POVM matrix in a Unitary?

quantum-gate mathematics unitarity

modified Jul 6 at 8:39 user12984287 502

2

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1

answer

65

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Confusion regarding time complexity in the HHL algorithm

algorithm hhl-algorithm

modified Jul 7 at 10:00 zhenyu 21

1

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2

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61

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How can a half-wave plate affect the position qubit and not the polarization qubit of a photon?

quantum-gate deutsch-jozsa-algorithm photonics

answered Jul 8 at 6:46 Aleksey Zhuravlev 25

1

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0

answers

38

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Step-by-step passages in calculation

mathematics matrix-representation textbook-and-exercises

modified Jul 7 at 12:50 glS 10.2k

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