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.
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How does one get the right counts for the measurement of a single qubit in the presence of noise with qiskit?
I am using a single qubit in the IBM quantum lab running on ibm_armonk and it is simulated with real noise, however when I try to measure out a state where the coefficient of the 0 state is less than ...
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How to choose $\beta$ in Gaussian derivative component of DRAG pulse?
From definition of the DRAG pulse it is: $$f(x)=Gaussian+1j*\beta*(-(x-duration/2)/\sigma^2)Gaussian,$$
where $Gaussian(x, amp, \sigma)=amp*e^{-(1/2)*(x-duration/2)^2/\sigma^2}$.
If I try it in ...
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Adding trainable weights to feature inputs for a CircuitQNN?
Currently I'm trying to get together a QNN that can be trained to classify the normalized (-1, 1) IRIS Dataset on all 3 classes. For this I am using Qiskit's ...
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2answers
40 views
Are we using the real-time error information in simulating noise on qasm?
I'm trying to run some quantum circuits on qasm simulator using the noise information from IBM Q quantum device:
...
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21 views
unsymmetric observable estimation by Qiskit
Assume $|i\rangle,i\in[1,m]$ is a set of state, like the Fock states for Fermions. The question is how to compute the quantity ,$\langle i|H|j\rangle,i,j\in[1,m]$, in qiskit. The $H$ here is the qubit ...
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37 views
How to separate initializing qubits from runing algorithm several times
I have read several papers about quantum computing. It looks like any algorithm consists of several phases. For example in Grover algorithm initially qubits must be initialized from reset state $|0\...
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1answer
38 views
How to set hyper parameters for a Variational Quantum Classifier (qiskit)?
I am trying to implement a Variational Quantum Classifier using qiskit's VQC. I have set the feature map to ZZFeatureMap and am using the ...
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30 views
Qiskit's classifier is not optimising the weights
I am using qiskit's VQC to build a classifier. Dimensionality of the data is 2 and number of classes are 4. The feature map I used is ZZFeatureMap and ansatz is the RealAplitudes. Then entanglement ...
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7 views
Qiskit's draw only shows the circuit's name and not the architecture [migrated]
Upon trying to draw a ZZFeatureMap instance, I only see the name "ZZFeatureMap" and not it's architecture. Please find the code snippet and output ...
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29 views
Two body integral calculation taking too long
I'm running the most recent version of qiskit and am trying to run H2 in the cc-pvtz basis. However, it is taking an incredibly long time. This is what my code looks like:
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1answer
44 views
How is transformation for measurement in an arbitrary basis derived?
I started with Qiskit today and find it very exciting.
As a first question I want to understand how to measure an arbitrary state $|\Psi\rangle$ not in the basis of ...
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1answer
36 views
How to write a code to made envelope function equal to $\pi$ to result in an X gate?
$$
\hat U_d = \exp\Big( -i\underbrace{\frac{Q}{2}\int_0^T A(t^\prime)\mathop{dt^\prime}}_{\Theta(t)} \hat\sigma_x \Big)
$$
This equation is a Unitary transformation applied to a qubit from time $t = 0$...
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24 views
How do you access stored Ramsey experiment frequency?
What is the stored frequency for the Ramsey experiment and how can this stored frequency be accessed? Is there a backend.get(frequency) command for this frequency?
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44 views
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Working with higher energy states in Qiskit Experiments
I'm looking at the source code for the Qiskit Experiments module and see that the EFRabi class subclasses the Rabi class with the intent of calibrating rotations between the 1 and 2 states instead of ...
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2answers
307 views
What is the computational complexity in initializing a quantum register?
I'm trying to figure out what is the computational complexity of initializing a quantum register of N qubits.
For my research, I have used the initialize method of qiskit, in which you set the ...
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13 views
Confusion about Mitiq folding for zero noise extrapolation
I'm reading the mitiq zero noise extrapolation documentation and I just can't make sense of how the scale_factor for folding work.
"The minimum scale factor is one (which corresponds to folding ...
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1answer
23 views
have to process 512×512 pixel image will it be possible in Qiskit. what hardware requirement will be?
I'm working on Quantum image processing of satellite images. I'm completely a beginner also I'm learning it by my own that's why I need help. Can you please help me out I want to process the image of ...
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23 views
from hello_qiskit import run_puzzle results in error
I am working my way through the beta version of the Qiskit textbook.
Everything was going fine until I got to the Visualizing Entanglement section and had some exercises to complete.
All of the ...
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55 views
How can I create a Qiskit function producing a quantum circuit such that $\langle Z^{\otimes n}\rangle=J_{n-1}/2^{n-1}$?
Problem:
Create a function circ(n) that returns an $n$-qubits quantum circuit that, when measured in the $Z^{\otimes n}$ basis, should yield the following ...
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1answer
39 views
Where does the "correction" in quantum error correction occur, specifically when using repetition codes?
I'm reading the part of the qiskit textbook that deals with this (https://qiskit.org/textbook/ch-quantum-hardware/error-correction-repetition-code.html) and so far it seems as though they're just ...
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1answer
124 views
Getting non-Clifford after performing several Clifford gates in qiskit
I'm trying to test Clifford gates in qiskit according to the table in Fault-tolerant SQ, page 101. I tried 4 Cliffords in the test $$-X/2 - X -X/2,Y/2,X/2 - -X/2,Y/2,-X/2$$
using the following code
<...
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1answer
51 views
How to create a quantum circuit to implement the same operations but acting on different qubits?
I want the draw the quantum circuit of the following Hamiltonian:
$$H = - 4 \times X\otimes X\otimes X\otimes X - 4\times Z\otimes Z\otimes Z \otimes Z$$.
I have been able to draw the circuits of $ - ...
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76 views
Which quantum computing frame is suitable for optimization problems?
As in the computer world, not all programming languages are suitable for everything.
Php = Backend
Javascript = Frontend
Data Analsys/ML = Python
embedded systems = C
Mobilphone/apps = Android / Swift
...
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1answer
62 views
Is it possible to perform $z$ rotation in Qiskit with just $x$ and $y$ rotations?
Is it possible to perform $z$ rotation in Qiskit with just $x$ and $y$ rotations?
I tried the following:
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2answers
80 views
Find a unitary to prepare state $|0\rangle$ to a specific vector
I am working with Variational Quantum Linear Solver (VQLS) algorithm, where it needs to prepare a control_b circuit.
Assume b is 1d with $ 2^n $ elements in it.
$$ {\bf Ax = b} \tag{1}$$
I need to ...
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1answer
22 views
Qiskit noise model question (from textbook)
I'm reading the chapter Introduction to Quantum Error Correction using Repetition Codes and a code example demonstrates how to add depolarizing and pauli error. I have several questions.
Is it not ...
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1answer
35 views
Can someone please explain how the syndrome bit still ends up being 0 in this quantum error correction circuit using repetition code?
I'm not too great at dealing with superpositions and applying the CNOT gate when superpositions are involved. Can you go through it in detail each gate using math/matrices etc. It's based on the ...
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37 views
How's the depolarization channel applied to one qubit circuits?
Suppose that in all gates used in a one qubit circuit the depolarization channel is applied, i.e.
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24 views
Papers explaining how to use ShiftPhase(theta) instruction in Qiskit
When dealing with the energy states, if we apply a rotation in 0-1 space it will affect the space of 1-2 and contrary. However, I am lacking documents about this phase change between these spaces and ...
3
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1answer
86 views
Implement the classical shadow coding error?
I'm trying to reproduce the basic method of classical shadow, which is based on the tutorial of pennylane. However, I've met some realization problems here when I finish reading the tutorial of ...
3
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1answer
41 views
How to apply Euler's formula to $Z$ rotations such as $e^{i\pi/8 Z}$?
I was following the Qiskit textbook and wanted to show that $R_z (\pi/4) = e^{i \pi/8 Z}$.
Plugging $\pi/4$ in for $\theta$ in the matrix from this page $ \begin{bmatrix}
e^{-i \pi/8} & 0 \\
0 &...
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1answer
48 views
Amplitude encoding: distinction between negative and positive real values
I want to encode two vectors into qubits and compute a distance between them that corresponds/is proportional to the euclidian distance of the real vectors.
The encoding I use is
A) qiskit ...
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1answer
49 views
Why in quatum coin toss, when starting from state $|1\rangle$, we get $|-\rangle$?
I was reading qiskit's text book, there I found that for a Double quantum coin toss, we have negative probability amplitude for $|1\rangle$ state when we starts from $|1\rangle$ state.
Link : https://...
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2answers
42 views
Is it possible to use the mitigation process on a teleportation circuit?
Is it possible to use the mitigation process on a teleportation circuit? Sorry, i'm still starting, if someone can get me out of this doubt, I would appreciate it. The circuit I'm trying to make this ...
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1answer
59 views
How to apply gates based on a random decision on the IBM quantum computer?
I want to run a circuit on an IBM quantum computer, and this circuit involves gates that are either applied or not based on a (classical) random decision.
As a minimal example, imagine a circuit with ...
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26 views
How to run Qiskit's transpile in parallel in Windows?
I want to execute qiskit transpile function in parallel.
My experiment environment OS is Windows, and the Qiskit version is 0.29.1.
I already asked one question here, and I also changed the file ...
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1answer
55 views
Expected outcome of adding two PauliOp
first of all, I would probably report this as a bug if I was confident enough in my QC abilities. As it stands, I've just started out, so I'm phrasing it as a question.
From what I can tell, adding ...
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16 views
Exacting specific results in running a list of tomography circuit
I run a test on tomography of two circuits like this:
...
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1answer
66 views
Does Qiskit transpiler execute multiple circuits in parallel? [closed]
I have something to ask about Qiskit's transpiler.
Before that, please check this document.
...
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1answer
65 views
Enforcing a particular layout mapping in Qiskit
I would like to ask how to set a particular layout during transpiling. I guess that the layout can be set by the initial_layout parameter in the transpiler. However,...
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1answer
48 views
Is noise the only reason that makes the results of Quantum Support Vector Machine (QSVM) and Classical SVM differ, when we use a large dataset?
When I used and tested out the Quantum Support Vector Machine for just 120 samples of a large dataset (Training - 100 and Testing - 20). Its kernel classification results were quite close to the ...
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0answers
21 views
How to design a RF-SQUID qubit by Qiskit Metal?
I am now learning how to use Qiskit Metal to design superconducting circuits. I found that there are only several transmon qubits in the library. Can I design an RF-SQUID qubit by using Qiskit metal?
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0answers
40 views
Writing circuits in Qiskit using only Clifford and T gates
Is there a way in Qiskit to write my circuit using only Clifford and T gates (CX, S, H, T and I think also $S^\dagger$ and $T^\dagger$)? With the function compile (with aer simulator) it gives me some ...
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1answer
78 views
Is there a faster way to do real-time error mitigation in qiskit?
I'm working on the readout error mitigation on a set of results obtained from different quantum circuits. The method I want to apply is to generate the confusion matrix for each quantum circuit (as ...
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2answers
49 views
qiskit transpile initial_layout determination
So, I am fairly new to Qiskit, and I've been following Qiskit textbook recently. In the chapter 7, where the QC lab exercises are located, in the first lab when working on the real hardware it is ...
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1answer
101 views
Qiskit's QFT not returning the expected state
I'm currently going through the lab problems for the Qiskit course here. I'm trying to finish lab set number 3 on QPE but I can't seem to get the desired output, even from the solution notebook. I'm ...
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1answer
42 views
Applying $R^{'\dagger}_{xz}$ in gate teleportation
In figure 4 of the paper Quantum Teleportation is a Universal Computational Primitive, the authors show a circuit for applying a unitary $U$ fault-tolerantly via teleportation. I'll paste the figure ...
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Hi My Dears, I was working on the Quadratic Equation Solution Technique Using Quantum? [closed]
I was working on the Quadratic Equation Solution Technique Using Quantum ? But it seems to me that there might be no Quantum Benefit for it.
If anyone can kindly code this in a cleaver way , Please do ...
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1answer
69 views
Error when running a VQE circuit in IBMQ backends
I want to run a VQE circuit of 4 qubits for a simple Hamiltonian with Qiskit. The circuit run smoothly in simulators. However, when I try to implement it on real IBM' quantum computers it gives me the ...
