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.

214 questions with no upvoted or accepted answers
Filter by
Sorted by
Tagged with
1
vote
1answer
57 views

how can we save a model using qiskit_machine_learning?

How can we save a trained model using Qiskit Machine Learning library? I've built a VQC classification model and once finished, I'd like to save the different models to be loaded later. There is a <...
1
vote
0answers
66 views

Error when computing the self-designed gradient in qiskit

I had question with the way to define a new kind of gradient to improve the performance of VQE. The gradient formula I used consists of multiply energy (measurement result of the Hamiltonian) with the ...
1
vote
1answer
62 views

Trying to connect IBM Quantum to External API

Is it possible to connect a quantum computer to openlibary.org API? How do I find the public IP address to my quantum instance?
1
vote
0answers
28 views

Difference in HLL applications

I am new to Qiskit and I have seen two types of simple 2X2 $Ax=b$ system solutions. I am wondering what the difference is exactly. They both occur on a simulator backend, but the first gives me a ...
1
vote
0answers
35 views

Quantum Machine Learning: how to get effective time of training/scoring

I am trying to examine the potential of Quantum Machine learning in terms of performance and time compared to classical algorithms. I am using both Qiskit's QSVM and scikit's SVM with Qiskit Quantum ...
1
vote
0answers
61 views

Implementation of the Phase Estimation algorithm

I've been working on implementing quantum phase estimation in Qiskit for a $2^n \times 2^n$ Hamiltonian as part of my bachelor project, I'm using Trotterization as my Hamiltonian simulation of choice ...
1
vote
0answers
61 views

Are inconsistent results between different VQE runs justified?

I made this post a while ago, where I learned I could use qiskit's VQE to calculate (or approximate) the Transverse Field Ising Hamiltonian and other similar Hamiltonians. After working with my code ...
1
vote
0answers
88 views

How to load time-series stock data into quantum amplitude estimation

Now I got some time-series data as showing example below: I have spent a period of time realizing the QAE from qiskit, and I found that the tutorial used uncertainty model to reproduce data, while I ...
1
vote
0answers
39 views

What is the kernel used in the IBM Qiskit's source code?

I want to redefine the QSVM code for a different kernel. But what is the kernel actually used in the IBM Qiskit's source code? And where is it defined, exactly. QSVM on Qiskit.
1
vote
1answer
88 views

Running qiskit on jupyter notebook certverification error: unable to get local user certificate

I have code which runs on the IBMQ website perfectly, however copying and pasting the same code (and including my API token) the same code does not run when I try and run it on a real quantum computer ...
1
vote
0answers
119 views

Qiskit Tomography and Noise Mitigation with a Measurement Mid-Execution

I'm struggling to get a program running where I have a circuit with a measurement and reset mid-execution and I want to use noise mitigation and state tomography together. The circuit is defined ...
1
vote
0answers
54 views

How to transform fermionic operators in qiskit

I encountered some problems when using the qiskit pakage to define the 2-electron reduced density matrix (2-RDM), which is a 4-index tensor, $\langle a_i^\dagger a_j^\dagger a_k a_l\rangle$. I need to ...
1
vote
2answers
142 views

Question on qiskit.circuit.library.PiecewiseChebyshev Qiskit circuit library

This question follows the post https://quantumcomputing.stackexchange.com/posts/15070/. I am working on an implementation of HHL algorithm, to do so, I need to map $|\lambda\rangle\mapsto |\arcsin(\...
1
vote
0answers
15 views

Need Help in QGAN function to load higher dimentional data

I have a query that I am using qiskit.aqua.algorithms.QGAN library and using the qgan function and I am having difficulty in loading data of dimension 1000 rows x 10 columns. I am following qiskit's ...
1
vote
0answers
63 views

How to divide one quantum circuit into multiple sub-circuits in qiskit?

While I'm simulating one Big quantum circuit in Qiskit, I wonder how we can divide one big quantum circuit into several sub-circuits. I looked in Qiskit API documents, but I couldn't find it. Is there ...
1
vote
1answer
94 views

Need some help with simulating molecules with VQE

I have studied the example of the simulation of LiH molecule in Learning Quantum Computation using Qiskit. It is available on this link: https://qiskit.org/textbook/ch-applications/vqe-molecules.html#...
1
vote
3answers
72 views

Quantum Error Correction implementation in Qiskit, OpenQASM or other languages based on Python

Where can we find example(s) of implementation code in a programming language of Quantum Error Correction, whether with the standard method of measurement or the automatic method without measurement (...
1
vote
0answers
49 views

Will there be any difference in solution for a weighted and unweighted graph? I mean is there any relation between weight and solution?

I was working on max-cut problem. To do I have been given a graph of unweighted version, and I have to convert it into weighted version. I did it using qiskit. Now I was playing around the code, hence ...
1
vote
0answers
50 views

How to implement Majority Vote

I am trying to boost the success propability of standart phase estimation by repeating the procedure enought times and taking a majority vote that will be encoded in a quantum register. My problem is ...
1
vote
0answers
55 views

Why Measurement Error Mitigation does not seem to improve the result of VQE?

I try to follow https://github.com/Qiskit/qiskit-tutorials/blob/master/tutorials/algorithms/03_vqe_simulation_with_noise.ipynb to perform measurement error mitigation for calculating H2 energy with ...
1
vote
0answers
29 views

Why do I get the error 'IBMQManagedResultDataNotAvailable'?

I'm trying to use IBMQ job manager to submit a list of quantum circuits (300 of them in total) to 'ibmq_16_melbourne'. This is what the job status looks like on IBM Quantum Experience: I don't know ...
1
vote
0answers
74 views

Why qiskit.execute runs much slower for inputs with multiple circuits, and how to speed it up?

I am using the "execute" in qiskit to run experiments for two circuits, and it turns out that "execute" runs much slower if the two circuits are run simultaneously, compared to if ...
1
vote
0answers
109 views

How can I fix the BrokenProcessPool error in Qiskit?

I'm running a set of quantum circuits using the ibmq_qasm_simulator. However, sometimes my code works for the simulation, but sometimes it doesn't, and the system ...
1
vote
2answers
92 views

Qiskit: simulate a circuit using a backend noise model

...
1
vote
2answers
82 views

How to use VQE function in Qiskit

As part of a project I'm working on, I want to use VQE algorithm to calculate the minimal eigenvalue for given Hamiltonian. I use Qiskit on IBM UI online. The Hamiltonian is given as a sum of tensor ...
1
vote
0answers
114 views

Solving Poisson's equation with Quantum Fourier Transform

I found Quantum Fourier Transform in the Qiskit textbook, but I'm looking specifically for how to solve Poisson's equation with the Quantum Fourier transform. Are there any references that talk about ...
1
vote
0answers
39 views

qasm_simulator generating identical results repeatedly

I wish to run a very simple circuit on the qasm_simulator backend. My circuit is ...
1
vote
1answer
152 views

Why do the qasm_simulator runtimes vary significantly for different IBMQ CouplingMap/NoiseModels?

I have been running VQE experiments locally using the qasm_simulator with actual IBMQBackend NoiseModels as shown in the Qiskit Textbook. I have noticed that the ...
1
vote
0answers
44 views

Report measurement components for a given Hamiltonian measurement

I was wondering if there is a possibility to report measurement components when reporting the final expectation values of a qubit operator. For example, if we look at a simple Hydrogen molecule ...
1
vote
0answers
280 views

Can one use a quantum circuit as a pathfinding algorithm?

I've been learning about quantum computing, and I noticed that another way to describe the state vector is as a path in a binary tree where each level of tree represents another qubit, each node ...
1
vote
0answers
147 views

qiskit - MCMT - base gate acting on only one qubit

I want to reduce the depth of a ucrz gate acting on multiple qubits with ancilla qubits in qiskit. One way to do this could be the mcmt implementation with ...
1
vote
0answers
47 views

Qiskit function phase_amplitude_damping_error

I am reading about the noise models that can be simulated in Qiskit and I found out the phase_amplitude_damping_error function. I read about it and it seems to be a function that simulates a combined ...
1
vote
0answers
90 views

Changing the Basis

I am attempting to use a VQE algorithm to find the ground state of a deuterium nucleus by applying a constructed hamiltonian to an ansatz state with one parameter created by a circuit. While I am ...
1
vote
0answers
60 views

Help Understanding Line in Source Code

In Qiskit's implementation of the HHL algorithm, they have the following line at the end of their code that allows them to compute the global phase we need to add on to the solution. ...
1
vote
0answers
31 views

There seems to be a bias against states with more 1s, in IBM's calibration matrix generator: What are the consequences and possible solutions?

Qiskit's function CompleteMeasFitter builds a calibration matrix in this way (2 qubit case): Everything is initialized in the state $|00\rangle$, which is the ...
1
vote
0answers
210 views

Problem with installing Qiskit on Android with Termux emulator

Termux has some issues with cmake, therefore qiskit-aer-0.5.2 installation returns error 1. ...
1
vote
0answers
38 views

How to ignore spins is Qiskit chemistry package?

Is it possible to use built-in qiskit.chemistry tools, such as VQE, UCCSD, etc., without ...
1
vote
0answers
48 views

Creating qubit operators for optimization problem

There is DOcplex module that generates WeightedPauliOperator for the DOcplex Model by calling docplex.get_operator(model). I ...
1
vote
1answer
121 views

How to get running time for each circuit executed on IBM's quantum processors in one round?

I want to execute multiple circuits in one round on IBM's backends, especially the 16-qubit one, to save time. For instance, ...
1
vote
0answers
67 views

ibmq_qasm_simulator from IBMQ provider and qasm_simulator from Aer provider gives different results

I'm running an experiment first on qasm_simulator backend from Aer provider and the most frequent result is the correct one with ...
1
vote
0answers
156 views

Creating Bell States with CNOT conditioned to the control qubit being set to zero

I was using qiskit to generate all of the Bell States. I created the following circuits for each state: $|\Phi^+\rangle :$ $|\Phi^-\rangle :$ $|\Psi^+\rangle :$ $|\Psi^-\rangle :$ The $|\Psi^\pm\...
1
vote
0answers
35 views

Error in qiskit.aqua.operator

I want to implement this thing: Operator([[3, Pauli([1,0,0], [0,0,0])], [2, Pauli([0,0,0],[0,0,3])]]) But while doing this there is an error in ...
1
vote
1answer
820 views

Updating qiskit doesn't update qiskit version from Spyder

I installed qiskit using directions at https://qiskit.org/documentation/install.html I also have ...
1
vote
0answers
23 views

Confusion regarding subset_fitter() functionality from CompleteMeasurementFitter() in Qiskit.Ignis

I have been experimenting with the measurement mitigation module in Qiskit Ignis lately. I determined a calibration matrix $M$ with the help of ...
1
vote
0answers
260 views

Qiskit not installing properly on pyCharm CE

I have installed qiskit through my terminal using pip3 install qiskit. But when I try to import all from it in my coding software, it returns a M...
1
vote
0answers
77 views

How can I run programs in test folder Github Qiskit

I am new to GitHub/Python - please tell me how can I run programs in https://github.com/Qiskit/qiskit-aqua/tree/master/test and its sub directories in Jupyter. I am connected to IBM Q Expereince. I am ...
1
vote
0answers
41 views

Loading old results for Data reprocessing

I want to process some old data again. How do I load old data retrieved from IBM-Q into a new program? I've downloaded the relevant .json file, but I don't know how to use it like I would have a new ...
1
vote
1answer
159 views

from qiskit.aqua import... ImportError: DLL load failed: The specified module could not be found

Dear team and developers. I am using qiskit on Python 36, windows 64bits I have the same identical problem of Import from qiskit-aqua error But the suggested solution (installing Numpy+mkl, I did it!) ...
1
vote
0answers
110 views

deliver a quantum register to/from a function in qiskit

Can I create a function in qiskit which receive a quantum register as an argument, and/or returns a quantum register? In the example below, I created a quantum register, and a quantum circuit which ...
1
vote
0answers
241 views

A question about qiskit's WeightedPauliOperator.evolve method for IPEA (IQPE) implementation

I'm doing an implementation/tutorial of the iterative phase estimation algorithm (IPEA) and have a problem. My Hamiltonian is a diagonal matrix $H = \begin{pmatrix} E_1 & 0 \\ 0 & E_2\end{...