Questions tagged [qiskit]

Quantum Software Development Kit for writing quantum computing experiments, programs, and applications. If appropriate, also use the [programming] tag.

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Graphing the decoherence of qubits being used to perform an algorithm

How would I be able to graph the decoherence of qubits being used to perform an algorithm? I'm working with the IBMQ Qiskit framework and I'm trying to write a program that allows me to find the ...
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1answer
86 views

Use Qiskit in other programming languages (C#, JavaScript and Lua)

I am exploring using Qiskit in other programming languages for game development, such as C# (for Unity game engine), JavaScript (Phaser.io) and Lua (LÖVE2D). Is there a general way to call Qiskit ...
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40 views

Vary parameter between shots

Is it possible to tell Qiskit to execute a parameterized gate where the parameter varies between shots? Let's say, for whatever reason, I'd like to speed up the dephasing of a qubit during a run. I ...
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506 views

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

I need to make a general implementation of Shor's algorithm that factors, at least, N = 15. I have been able to perform an implementation that works in simulators, with ProjectQ, but when running it ...
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94 views

Results from looped experiments on IBM Q different than individual experiments

I'm experiencing an issue while using Qiskit where the counts from a job return vastly different values when ran in a loop or as an array of circuits as opposed to single experiments when run by ...
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39 views

How does batching work in the optimizer loop of the VQC algorithm in Qiskit Aqua?

I've playing around with a binary classification problem with a dataset of size 1000 examples and 5 features. I'm using the VQC algorithm from the Qiskit package the that uses a feature map and a ...
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2answers
330 views

Qiskit installation failing: VC++ 2017 not found

I tried to follow the web instructions to load Qiskit, including VC++ 2017 Redistributable, but I get many errors upon installation. The gist seems to be that VC++ 2017 wasn't found. Some results ...
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112 views

Problem with measurement error mitigation using VQE

I am attempting to mitigate measurement error while running on one of IBM's real devices and am doing so by passing CompleteMeasFitter into ...
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56 views

`execute()` hangs and eats memory

Used memory-profiler to check why I get memory spikes in what I though were small circuits. The circuit itself is constructed using ...
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134 views

Is there a way to develop a multiple controlled X or Z gate on Qiskit without using ancillary qubits?

I know for instance I can derive a cccX gate using 2 Toffoli gates on 5 qubit wire or ccccX with 3 Toffoli gates and 7 qubits and so on. you will notice the depth is increasing as the number of ...
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236 views

Measuring Coherence Length for T1 and T2 values with IBMQ Experience

So I'm currently working on a little program to measure how long the coherence time of a qubit is. Basically the idea is to initialise a qubit with a X or H gate then stick in a varying amount of ...
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66 views

Bell State 11 not working for parity curve

I am currently writing a script to automate the creation of parity curves for a 2 qubit bell state and then calculate fidelity and proving entanglement from that (inspired by this paper). It was going ...
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112 views

Measurement inconsistency in Qiskit

I am using Qiskit in an algorithm. In the end, I am measuring exactly a register of 4 qubits but the histograms show states with 5 qubits. This is the code I used: ...
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67 views

How can I express controlled unitary operation in QPE of this implementation of HHL?

I have found this implementation of HHL, and I don't understand why the controlled unitary operation is expressed in the form of $\exp(i t_0 A/2)$ and $\exp(i t_0 A/4)$. The rotation of $\pi$ and $\...
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67 views

What are reasonable noise/dephasing parameters for QuEST to emulate state-of-the-art quantum computers?

The QuEST code allows for simulation of quantum computers taking dephasing and depolarizing noise into account via one and two qubit dephasing and depolarization. What are realistic parameters for ...
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463 views

Qiskit Python program cannot connect to QE API

I am just getting started with Qiskit and IBM Quantum Experience, so please forgive my newby question. I have a IBM Quantum Experience account and I generated an API token. I used the generated ...
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24 views

How to simulate spin-1 systems with qiskit or on the IBMQ platform?

I am wondering how to simulate spin-1 systems with qiskit or on the IBMQ platform? I want to initialize a qudit (a spin-1 system), and then define the usual operations (such as Sx, Sy, and Sz) on the ...
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35 views

Easiest hash function to implement on Qiskit

Trying to build an Oracle circuit for Grover's algorithm that will try to find a desired input in order to get a certain output of a hash function. Was wondering if there were any 4 or 8 bit hash ...
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57 views

Simulation for the [5,1,3] stabilizer code in Qiskit

Sorry that I keep asking questions for the same subject. It is driving me crazy. I have followed the [5,1,3] stabilizer code circuit designed by Gottesman in page 35 in his paper (also illustrated in ...
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3answers
80 views

Pauli I in eoh procedure doesn't become a global phase gate in qiskit evolution_instruction method. Possible consequences

If one has two qubits in arbitrary stats and wishes to apply a controlled version of some global phase gate $P(\varphi) = \begin{pmatrix} e^{i\varphi} & 0 \\ 0 & e^{i\varphi} \end{pmatrix}$ ...
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1answer
129 views

How can we construct a square root of NOT gate in Qiskit and IBMQ circuit composer using universal gates?

I have tried it with decomposing controlled S then conjugating with H gate. But I want to construct it using a minimum number of gates.
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67 views

Is it possible to simulate or replicate a cryptographic algorithm using Qiskit?

I would like to know if it is possible to recreate or simulate a cryptographic encryption algorithm like DES or AES using the quantum computing platform Qiskit from IBM?
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73 views

Running HHL tutorial on real backend

I tried to follow the HHL tutorial. Since the 8x8 problem is not realistically simulable (I stopped after a few minutes), I tried to make it run on another backend, starting on the easiest example: <...
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136 views

Error ERROR_TRANSPILING_JOB when trying to simulate the circuit

I'm trying to implement an algorithm (https://dl.acm.org/citation.cfm?id=1128034, basically a simple Grover Algorithm in which the oracle is made of a Fitness operator- some CNOT gates- and 2 adders) ...
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49 views

Hybrid classical-quantum linear solver based on the Neumann-Ulam method

I read this article on quantum linear solver based on the Neumann-Ulam method (here is a lesson about it). But the article has not a lot of details. Therefore I don't understand what is the algorithm ...
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476 views

Qiskit SDK problem

So I am getting this error when I fire the command on Ipython or Jupyter Notebook ...
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21 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...
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1answer
28 views

Qiskit - Z expectation value from counts?

For a given state $|\psi\rangle$, how would I work out $\langle\psi|Z|\psi\rangle$ ? If I run a quantum circuit and get the counts dictionary on qiskit, I get observables in the Z basis. For n=1 ...
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32 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 ...
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1answer
30 views

qiskit: IQFT acting on subsystem of reversed-ordered qubits state

I have a state psi as an ndarray of shape (2 ** 3,) s.t. psi[0]= amplitude of 000 ...
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31 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 ...
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40 views

Implementing QFT

I would like to know if there is a way to: Implement Quantum 'Functions' e.g the QFT of QFT* containing several single-qubit operations? Implement such operations on an arbitrary number of qubits and ...
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96 views

Decomposition of an arbitrary gate using given matrix in Qiskit

If I have an arbitrary non-unitary matrix of say $$ U = \begin{pmatrix} 1.5 & 0 & 0 & 0 \\ 0 & 0 & 0 & 1.6 \\ 0 & 0 & 1 & 0 \\ 0 & 1 & 0 & 0 \\ \end{...
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1answer
46 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 ...
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71 views

Openfermion to qiskit

Is there a direct way to go from an object generated in openfermion to objects usable in Qiskit. I can't find anything about any plugin. It's not too hard to translate into pyQuil and then to Qiskit ...
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50 views

Grover's algorithm for 3SAT problem gives erroneous results

I'm writing a code in python with qiskit that implements Grover's algorithm to solve the 3-SAT problem, but when I run it it doesn't give the correct annswer. I've checked the circuit with the ...
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52 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{...
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35 views

OpenPulse: Where to get current pulse definitions for standard gates?

Is backend.defaults().cmd_def and backend.defaults().pulse_library kept updated regularly? Is this the correct place to pull the best calibrated pulses for the standard gates? I am working on a ...
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46 views

Exponentiating Hermitian Matrix for use in QPE/HHL

I am currently trying to understand HHL by implementing a very inefficient Qiskit simulation script that performs HHL on an arbitrary hermitian matrix $A$ and a vector $b$. Because I am currently ...
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47 views

In Grover, how to implement oracle and amplification using Qiskit?

I found some examples of implementing the oracle when the marked state is $|000\rangle$. But how can we know what gate we should use inside of the oracle? Besides, for the part implementation, the ...
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55 views

Many jobs hanging after creating

I am running a VQE calculation running from a cluster using nohup. However, some of my jobs keep hanging with 'creating' and therefore my VQE is not converging/not working. However, at the same time,...
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38 views

Suggestions for hybrid factoring algorithm on DWave and Qiskit

I was wondering if the multi-prime factoring problem can be solved in a hybrid approach using DWave (to factor) and Shor's algorithm (in Qiskit)? Please let me know your thoughts. Thanks!
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78 views

'ERROR: QasmSimulator: Circuit cannot be run using available methods.'

I used the following code. Can anyone say what that error is about? ...
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273 views

Job execution issue while using IBMQ Experience

I am trying to run QSVM algorithm on the IBMQ backend devices using the API_TOKEN. Below is the snippet of the code that I am running. The code fails the validation test and throws an exception after ...
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0answers
233 views

Please help: get_statevector gives wrong result in qiskit

I simulated the circuit below in qiskit and used the statevector simulator to extract the statevector: The resulting statevector that it gave me was: array([ 0.5+0.j, -0.5+0.j, 0.5+0.j, 0.5+0.j]) ...
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64 views

Quantum based protein folding, prototype

Where I can read about protein folding on quantum computer (Qiskit will be ideal variant) with simple examples? Thanks
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53 views

About a Qiskit Function

I want to understand this Qiskit function (a function for creating the gate CNX with Python): more specifically i don't understand what's the rotations (Y and Z) over the qubits for ? I added inline ...
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639 views

How to run quantum SVM algorithm from Qiskit in real IBM Quantum Computer using IBMQ?

I'm trying to run QSVM algorithm in IBMQ experience, want to run in one of those real quantum computers. ...
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0answers
80 views

Exception encountered while running quantum-enhanced support vector machines

I am trying to run the code of the notebook example aqua/artificial_intelligence/qsvm_kernel_classification.ipynb. I save it in a python file and I have an exception at runtime the display of ...
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11 views

Error parameters from Qiskit backends

In order to build a custom noise model in Qiskit Aer, I requested the error parameters from different backends and got 3 (9) parameters for each single-qubit (two-qubit) gate as output. However, I ...