Unanswered Questions
554 questions with no upvoted or accepted answers
4
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answers
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Qiskit QAOA optimization does not work when setting simulation seed in AerSampler
I am using Qiskit's QAOA for optimization and I would like to extract the probabilities distribution obtained in the optimization loop when running the circuit with the optimal parameters set. To do ...
- 41
4
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0
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408
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The error with Estimator primitive due to the qiskit version
The code that I follow is from this tutorial.
But there are some errors due to the version of qiskit on the Estimator primitive
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- 5,969
4
votes
1
answer
128
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HHL for the pseudoinverse in Qiskit
The HHL algorithm can be modified to compute the pseudoinverse of $A$ as is shown here and here. Is there anyway to do this in Qiskit without coding the entire thing manually?
CommunityBot
- 1
4
votes
0
answers
191
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Apply a single-qubit channel between in between two circuits in Qiskit
Suppose, you have two parts of a circuit in Qiskit, qc1 and qc2 on any number of qubits such that the entire circuit is given by
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- 959
4
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33
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Qiskit: efficient way to create bound circuits?
I am running an optimization problem whose objective function $F(a)$ requires measuring N variational circuits $V_i(a)$ at each evaluation.
So, roughly, I have created N parametric circuits and I do:
<...
- 361
4
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0
answers
283
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Qiskit NoiseModel.from_backend gives wrong gate error
According to the Qiskit documentation, a gate error is simulated by a thermal relaxation channel followed by a depolarisation channel, where the parameter of the depolarisation channel is adjusted so ...
glS♦
- 26.9k
4
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0
answers
35
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How does it work QasmSimulator with the option "density matrix"?
I am making some simulations on IBM Quantum Lab and as backend I tried to use QasmSimulator(method = "density_matrix") in order to simulate noise. I wanted to know how this method works in ...
4
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0
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50
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Predator–prey theory
We have a project where we are supposed to simulate the predator–prey theory in qiskit. Can anyone help or suggest of any ways to start from somewhere because we are kinda lost.
- 11.8k
4
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0
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240
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How to implement a gate that generate a uniform superposition of all permutation of element
I'm looking for a quantum circuit that permits generating a uniform superposition of all possible permutations for example if we have as input $|0123\rangle$ the output will be the uniform ...
- 2,438
4
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95
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Why does running a pulse schedule for Bell circuit give incorrect counts?
As part of another project I need to be able to run a custom pulse schedule for a bell ciruit and measure the counts. However I am having a problem where running the scheduled circuit is giving counts ...
- 41
4
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0
answers
99
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What is the most efficient method to update the binary encoded values inside a quantum state?
We're implementing a QML algorithm in which we have to update the value stored inside a quantum state which is strictly unknown to us, by multiplying it with a real number classically stored with us. ...
- 91
4
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1
answer
308
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Does one measurement affect the following measurement errors in mid-circuit measurement?
Suppose I have a quantum circuit with a few measurements (say $N$) on a single qubit. Before all the measurements, I generated calibration circuits and the 2 by 2 calibration matrix for that qubit of ...
CommunityBot
- 1
4
votes
0
answers
68
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Why the pulse scheduler produces a different output from the original circuit?
As part of a larger code, I have to convert a quantum circuit into a Pulse scheduler. The problem is that the scheduler output is incompatible with the circuit output. In particular, the difference ...
glS♦
- 26.9k
4
votes
1
answer
171
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Can the ancilla for Qiskit's mcx with mode="recursion" be dirty?
I think their implementation is close to the one from here which does use a dirty ancilla, but I just want to make sure
CommunityBot
- 1
4
votes
0
answers
101
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Computing specific observable for a Clifford circuit
Given a clifford circuit, how can I simulate it efficiently to get the 2-RDM (reduced density matrix) $D^2=\langle a_i^\dagger a_j^\dagger a_k a_l\rangle$ in the presence of deplorizing error? The ...
glS♦
- 26.9k