Questions tagged [qiskit]
Qiskit is an open source SDK for working with quantum computers at the level of pulses, circuits and application modules. If appropriate, also use the [programming] tag.
1,519
questions
0
votes
0
answers
3
views
Get qiskit-native gates from a circuit containing custom gates
I have a custom gate in qiskit defined as follows:
...
0
votes
0
answers
3
views
Number of Qubits in UCCSD Ansatz Shows as 0
I'm trying to run a VQE using the UCCSD ansatz; however, when I initialize the ansatz, I get that there is no qubits that the ansatz acts on, while there should've been 4. The related excerpt from my ...
- 126
0
votes
0
answers
6
views
Is this Quantum Neural Network overfitting?
In the accuracy graphs (attached the graph images below) shown in this code (Binary Classification for Fraud Detection):
validation loss is greater than training loss
training accuracy is greater ...
- 1
1
vote
0
answers
16
views
On the Qiskit Txtbk page for TSP, how does the initial phase matrix work?
I am looking over the TSP on Qiskit's Textbook, link below:
https://qiskit.org/textbook/ch-paper-implementations/tsp.html#Building-the-Components-
In the general strategy part of the documentation, ...
- 21
0
votes
1
answer
19
views
Why does qutip run without errors, but cannot output a Bloch sphere graph?
This is the official demo(https://nbviewer.ipython.org/github/qutip/qutip-notebooks/blob/master/examples/visualization-exposition.ipynb). But after I run it, there is no error, but I can't output the ...
- 159
1
vote
1
answer
43
views
training parametric circuits in Qiskit
The following is an official example of qiskit training simple parameter circuits (https://learn.qiskit.org/summer-school/2021/lab4-introduction-training-quantum-circuits). But they mainly focus on ...
- 159
0
votes
1
answer
25
views
Pennylane:WireError: Did not find some of the wires <Wires = [0]> on device with wires <Wires = [tensor(18, requires_grad=True)]>
My proj is from
https://pennylane.ai/qml/demos/tutorial_rotoselect.html
In verifying the application of this theory in more complex circuits, the following problems occurred.
How to fix this, I tried ...
- 159
1
vote
1
answer
36
views
Clarification on the usage of class UCC of qiskit_nature
I am trying to develop a customized VQE algorithm in which I am making use of the class UCC of qiskit_nature. I am having trouble understanding the outputs of the methods of the class. I have ...
- 13
-1
votes
0
answers
37
views
IBM Certified Associate Developer - Quantum Computation - ASSESSMENT EXAM [closed]
I got a question concerning the Assessment Exam for the IBM qiskit quantum developer certification. How often do the assesment exams get updated?
I already did one but like to do another one.
Will I ...
- 21
2
votes
0
answers
28
views
How to calculate Quantum Discord for two qubit system using Qutip?
Quantum discord of a bipartite system can be determined as:
$${D_A}({\rho _{AB}}) = I({\rho _{AB}}) - {J_A}({\rho _{AB}}),$$
The subscript of $A$ denotes that the measurement has been performed on the ...
- 21
0
votes
0
answers
13
views
Performing QN-SPSA on hybrid quantum-classical neural networks
I had a question on the TorchConnector module in qiksit_machine_learning (based on this tutorial). If I'm not wrong, is ...
- 41
0
votes
1
answer
35
views
Compilation error occurred in qiskit natural gradient case
https://learn.qiskit.org/summer-school/2021/lab4-introduction-training-quantum-circuits
...
- 159
1
vote
0
answers
30
views
Does training a quantum circuit require the derivative of each quantum parameter?
https://www.youtube.com/watch?v=mEfyCvwcSkQ&list=PLOFEBzvs-VvqJwybFxkTiDzhf5E11p8BI&index=19
This doubt comes from Lab-4, the 2021 Qiskit Quantum Machine Learning Summer School. The specific ...
- 159
1
vote
0
answers
25
views
The relationship between number of shots and performance of quantum agent
What is the relationship between number of shots and the performance of quantum agent in Quantum neural network? and what is the limit of number of shoots in QASM simulator?
1
vote
0
answers
18
views
Applications that support low fidelity qubits generated by UQCM
I am studying Universal quantum cloning machines. I have found that two imperfect clones can be generated with fidelity of 83.33%. Where can we use these imperfect clones in quantum worlds? Can we use ...
- 33
0
votes
1
answer
29
views
How does CircuitQNN in qiskit machine learning calculate output probabiltiies?
This is a question I have based on this previous question on calculating quantum gradients in quantum-classical hybrid circuits. I would like to understand the output of the ...
- 41
0
votes
2
answers
49
views
How to repeatedly initialize a fixed quantum circuit, and the initialization vector is random？
I need to repeatedly input one random quantum state after another into a quantum circuit that has been designed and assigned parameters, and these quantum states will be used as input. I have tried
...
- 159
0
votes
2
answers
30
views
qiskit from Anaconda spyder: Missing module error
I'm a newcomer to qiskit, when I tried to import qiskit, it followed a ModuleNotFoundError: No module named 'qiskit._accelerate'. I've tried creating a new virtual environment and re-install qiskit, ...
- 13
1
vote
1
answer
20
views
What is "time in system" for a given job and how to retrieve?
I noticed that there is "time in system" for each job.
For example:
I was wondering what does this mean? I am guessing this means the time of the first shot starts on the quantum devices ...
- 11
1
vote
0
answers
39
views
Does Qasm Simulator add noise by default?
I am wondering if Qiskit QasmSimulator adds noise by default or not. I am asking because I have 2 circuits:
circuit 1: computes cosine similarity between two vectors
circuit 2: computes cosine ...
- 63
0
votes
2
answers
41
views
Qiskit - How to get statevector for each shot?
I have a simple circuit which I run for 10 shots:
...
1
vote
1
answer
33
views
how to get the backend_status using qiskit?
I was preparing for the exam and I was confused about how to get job and backend status using qiskit, do we use Job_monitor for both of them?
2
votes
1
answer
74
views
Qiskit custom multi controlled gate
I'm building a 3 qubit circuit with the control-ry rotation gate. The code is the following:
...
-1
votes
1
answer
51
views
How to map classical data onto a Hamiltonian
training for the Hamiltonian. And our general QNN neural network training starts from the classical data set. The general method is to program the classical data into a quantum state, so what if I ...
- 159
0
votes
1
answer
37
views
How to get statevector of qubits after running quantum circuits on IBMQ real hardware to calculate the fidelity of all qubits individually?
Is it possible to get the statevector while running quantum circuits on IBMQ real hardware? If getting the statevector is not possible can I still calculate the fidelity of a qubit somehow?. What I ...
- 33
1
vote
1
answer
61
views
Gradient descent for a quantum-classical hybrid neural network
I am working on implementing a quantum-classical hybrid neural network in qiskit where input data is encoded on a quantum circuit (with say 3 qubits) using a ...
- 41
-2
votes
1
answer
42
views
1
vote
1
answer
53
views
When factoring N=21 on IBMQ Devices with Shor's algorithm, does the quantum subroutine require modular exponentiation?
I am currently working on Qiskit code implementing Shor algorithm in the form of a quantum circuit. I am factoring $N = 21$ (into 3 and 7) using 5 qubits, with 3 qubits in the work register and 2 in ...
- 21
1
vote
1
answer
28
views
About the modification and naming of qiskit parameters？
Is the parameter angle of the above picture the same, that is, each door rotates by an equal angle? How to assign different parameters to them, such as a[0], a1 of the same name? Is it possible to ...
- 159
1
vote
1
answer
16
views
AttributeError: 'QuantumCircuit' object has no attribute 'save_statevector'
Hi i know the question was already asked but my case is slightly different.
I am trying to do the qiskit tutorial:
...
- 13
0
votes
0
answers
50
views
IBM Quantum Lab - Server unavailable or unreachable. Would you like to restart?
In the following circuit, I want to perform tomography on the qubits 0,1,2,3 after qubits 4,5,6,7,8,9 are measured.
I run the circuit using with measurement gates on qubits 4,5,6,7,8,9 with the ...
-3
votes
1
answer
34
views
Question about qiskit optimizer in Portfolio Optimization
we tried running the Portfolio Optimization code using qiskit with the optimizer:Sequential Least SQuares Programming optimizer.
FOr 10 stocks, it ran fine, For, 21 stocks it hung up. COuld anyone ...
- 27
1
vote
0
answers
40
views
What is the concrete difference between qiskit thermal_relaxation_error and phase_amplitude_damping_error?
What is the concrete difference between those two error models in qiskit.providers.aer.noise?
For phase_amplitude_damping_error ...
- 53
1
vote
2
answers
85
views
Stepwise $SU(2)$ Rotations on the Bloch Sphere from $\pi$ to $2\pi$
Based on the useful straight-forward answers to both of my former questions, on multiple rotations of a qubit and bloch sphere subplots, I was able to implement the following $SU(2)$ rotations:
At ...
- 278
1
vote
1
answer
45
views
Qiskit optimization_level values
Is there a clear explaination of how exactly optimization_level choice in qiskit's transpile() method affects on circuit? I expected to see some mathematical operations with the gates that similifies ...
0
votes
0
answers
37
views
How to retrieve the "counts" data as integers?
I'm trying to plot the counts for the same tensor state (00, say) over many runs, but I'm not sure how to access the data from the "counts" variable in a numerical format that is usable (...
- 1
-1
votes
1
answer
46
views
How to use matplotlib to draw a city state in Qiskit
How to use matplotlib to draw the following image, hoping that the 3D histogram is at the coordinate intersection?
I can only do it as follows
- 159
0
votes
1
answer
29
views
Does qiskit_ionq have the possibility of simulating quantum circuits with noise?
I'm using qiskit_ionq API for simulating quantum circuits on ionq devices. Currently, I'm using the ionq_simulator backend, but I think it performs noiseless ...
0
votes
1
answer
38
views
Why does qiskit's density matrix output obscure the text, can it make this picture better?
Obviously, the histogram here has covered the coordinate markers. Is there any way to make this state diagram look better?
- 159
0
votes
1
answer
39
views
References for two-local forms in QISKIT
I am using 'Two local' form of QISKIT as a waveform ansatz in VQE to compute ground state. QISKIT documentation does not provide references to all the entangling options. Is there any other place ...
- 35
1
vote
1
answer
37
views
How to declare non-binary decision variables in an optimization problem?
I am working on a logistics problem which require me to find the optimum quantity of product to be manufactured and also to be shipped to satisfy the customer demand. I have made a decision variable $...
2
votes
1
answer
126
views
How to implement subplots (several blochsphere plots) using qiskit?
Qiskit seems to use matplotlib for rendering bloch spheres under the hood. Therefore, it would be nice if we could also make use of matplotlib's subplot technique.
I would like to implement subplots, ...
- 278
1
vote
0
answers
40
views
What's the best way to design a circuit with logic gates that use the same input lines?
I am implementing a Carry Select Adder, the problem is that the circuit is quite complex to translate in Qiskit.
I need to use one (or multiple) line(s) as input for two (or more) gates.
In particular,...
- 11
2
votes
2
answers
68
views
Calculating the probability of a result after measurement using Ry, Rz, and Rx matrices
Broadly: I have noticed on the qiskit developer (assessment) exam there are many questions asking to calculate the probability after measurement however I generally have no idea how to do this without ...
0
votes
2
answers
54
views
Better plot_bloch_multivector within Qiskit?
I'd like the plot_bloch_multivector function (or some other function that I can use in Qiskit) to display a Bloch sphere in a way that makes it clear whether the arrow points toward the front of the ...
- 33
1
vote
2
answers
45
views
which device had the best Average coherence time?
These are the IBM backend overview, do: Avg.T1/T2: here stand for the Average decoherence time or coherence time?
0
votes
1
answer
24
views
Clarification about QTF proof regarding equality of QFT application and circuit application
I'm self learning quantum computing through IBM's Qiskit's learning section (which I really like), and I've stumbled across an inequality that I don't quite understand fully.
This must be really easy, ...
1
vote
1
answer
32
views
Implementing deutsch_problem(seed=None) and deutsch() from qiskit text
I'm attempting to work through the exercise at the end of https://learn.qiskit.org/course/ch-gates/phase-kickback#phase-8-0 where I am to build and implement Deutsch's algorithm. I understand that <...
- 13
0
votes
3
answers
40
views
How to get precise angle values in Qiskit while using initialize() function to generate arbitrary quantum state?
Is there any way to get the quantum gate values more precisely in qiskit?
For example, if I want to create 1/√3[|00⟩+|01⟩+|11⟩]. By using initialize() I get the following circuit by using the draw() ...
- 33
0
votes
1
answer
83
views
Help on PySCF library
I am a student and I am trying to use qiskit nature in order to calculate the ground state energy of a molecule. My probelm is that when I try to run the simulation an error message comes out:
...
