# Demos **URL:** https://discuss.pennylane.ai/c/demos/25.md?page=1 [Latest](https://discuss.pennylane.ai/latest.md) · [Categories](https://discuss.pennylane.ai/categories.md) **Page:** 2 --- ## [Qubit tapering / LiH](https://discuss.pennylane.ai/t/qubit-tapering-lih/7956)
**Author:** [@Julien](https://discuss.pennylane.ai/u/Julien)\ **Replies:** 15\ **Last updated:** [March 11, 2025, 12:28am UTC](https://discuss.pennylane.ai/t/qubit-tapering-lih/7956 "2025-03-11T00:28:02Z")
Hi, I have succesfully reproduced the qubit tapering demo at Qubit tapering | PennyLane Demos using the provided example HeH+ However when I replaced HeH+ by LiH I noticed a large difference in HF energy between t… --- ## [Quantum parameters generation in the Generative Quantum Eigensolver](https://discuss.pennylane.ai/t/quantum-parameters-generation-in-the-generative-quantum-eigensolver/8064)
**Author:** [@aaanikit](https://discuss.pennylane.ai/u/aaanikit)\ **Replies:** 1\ **Last updated:** [March 4, 2025, 11:43pm UTC](https://discuss.pennylane.ai/t/quantum-parameters-generation-in-the-generative-quantum-eigensolver/8064 "2025-03-04T23:43:42Z")
Hi! I successfully reproduced the demo GQE Training. I’m interesting why the parameters for generating the excitation pool are formed exactly as follows: op\_times = np.sort(np.array(\[-2\*\*k for k in range(1, 5)\] + \[2\*\*k … --- ## [Quantum Embedding For machine learning](https://discuss.pennylane.ai/t/quantum-embedding-for-machine-learning/8013)
**Author:** [@VIJAY\_KARANJKAR](https://discuss.pennylane.ai/u/VIJAY_KARANJKAR)\ **Replies:** 1\ **Last updated:** [February 19, 2025, 12:27am UTC](https://discuss.pennylane.ai/t/quantum-embedding-for-machine-learning/8013 "2025-02-19T00:27:17Z")
For Quantum Embeddings for Machine Learning research paper, what exactly can be used as the Loss function for training (to reproduce Hybrid Model results)? They mention Linear Loss function and Risk function, but I am no… --- ## [Qubit tapering demo jaxlib runtime error](https://discuss.pennylane.ai/t/qubit-tapering-demo-jaxlib-runtime-error/7917)
**Author:** [@Julien](https://discuss.pennylane.ai/u/Julien)\ **Replies:** 2\ **Last updated:** [January 30, 2025, 8:08pm UTC](https://discuss.pennylane.ai/t/qubit-tapering-demo-jaxlib-runtime-error/7917 "2025-01-30T20:08:04Z")
Hi, I am trying to run the code described here on Linux Ubuntu using pennylane 0.4.0 ; python 3.13 ; CUDA 12.6 ; jax 0.5.0 The code snippet below generates a jacs runtime error. Is a workaround known ? Would yo… --- ## [QFT: no qml.transforms.decompose](https://discuss.pennylane.ai/t/qft-no-qml-transforms-decompose/7894)
**Author:** [@mlowe](https://discuss.pennylane.ai/u/mlowe)\ **Replies:** 3\ **Last updated:** [January 29, 2025, 4:32pm UTC](https://discuss.pennylane.ai/t/qft-no-qml-transforms-decompose/7894 "2025-01-29T16:32:00Z")
I am following the tutorial on QFT (Intro to the Quantum Fourier Transform | PennyLane Demos). There is a command to expand the circuit to see the operators: @partial(qml.transforms.decompose, max\_expansion=1) This lin… --- ## [Questions about QCNN](https://discuss.pennylane.ai/t/questions-about-qcnn/7539)
**Author:** [@kou](https://discuss.pennylane.ai/u/kou)\ **Replies:** 5\ **Last updated:** [December 29, 2024, 3:13am UTC](https://discuss.pennylane.ai/t/questions-about-qcnn/7539 "2024-12-29T03:13:41Z")
Sorry for the basic question. I have a question about the following qcnn tutorial. This tutorial includes the following: 「we are not going to train the quantum convolution layer, 」 My understanding is that quantum ma… --- ## [A quantum convolutional neural network for detecting and classifying tungsten inert-gas welds \[Womanium Grant Winner + QSL Fellowship Nominee\]](https://discuss.pennylane.ai/t/a-quantum-convolutional-neural-network-for-detecting-and-classifying-tungsten-inert-gas-welds-womanium-grant-winner-qsl-fellowship-nominee/7456)
**Author:** [@mack.attack](https://discuss.pennylane.ai/u/mack.attack)\ **Replies:** 1\ **Last updated:** [November 5, 2024, 11:42pm UTC](https://discuss.pennylane.ai/t/a-quantum-convolutional-neural-network-for-detecting-and-classifying-tungsten-inert-gas-welds-womanium-grant-winner-qsl-fellowship-nominee/7456 "2024-11-05T23:42:11Z")
Last summer, ourr team implemented a quantum implementation of the TIG weld classification problem. It has shown some promise for small kernels and low depth, but unfortunately, the training process took too long. I am t… --- ## [Can not install kahypar in VsCode](https://discuss.pennylane.ai/t/can-not-install-kahypar-in-vscode/7388)
**Author:** [@leo07010](https://discuss.pennylane.ai/u/leo07010)\ **Replies:** 5\ **Last updated:** [October 25, 2024, 1:18pm UTC](https://discuss.pennylane.ai/t/can-not-install-kahypar-in-vscode/7388 "2024-10-25T13:18:29Z")
I am currently learning from the tutorial on quantum circuit cutting from the following link: In this tutorial, kahypar is required, but when I followed the steps on the kahypar GitHub page: I encountered an error as… --- ## [LCU demo comment](https://discuss.pennylane.ai/t/lcu-demo-comment/7316)
**Author:** [@sustik](https://discuss.pennylane.ai/u/sustik)\ **Replies:** 1\ **Last updated:** [October 18, 2024, 4:12am UTC](https://discuss.pennylane.ai/t/lcu-demo-comment/7316 "2024-10-18T04:12:13Z")
The article is valuable, but I wanted to point out that it is not explicitly stated that the implementation of the linear combination of unitaries is not a deterministic solution. There is a probability of failure when n… --- ## [Trapped ion quantum computers Demo](https://discuss.pennylane.ai/t/trapped-ion-quantum-computers-demo/7341)
**Author:** [@CatalinaAlbornoz](https://discuss.pennylane.ai/u/CatalinaAlbornoz)\ **Replies:** 0\ **Last updated:** [October 17, 2024, 9:28pm UTC](https://discuss.pennylane.ai/t/trapped-ion-quantum-computers-demo/7341 "2024-10-17T21:28:34Z")
Use this topic for questions related to the PennyLane Demo on Trapped ion quantum computers. --- ## [Tensor-network quantum circuits Demo](https://discuss.pennylane.ai/t/tensor-network-quantum-circuits-demo/7340)
**Author:** [@CatalinaAlbornoz](https://discuss.pennylane.ai/u/CatalinaAlbornoz)\ **Replies:** 0\ **Last updated:** [October 17, 2024, 7:46pm UTC](https://discuss.pennylane.ai/t/tensor-network-quantum-circuits-demo/7340 "2024-10-17T19:46:37Z")
Use this topic for questions related to the PennyLane Demo on Tensor-network quantum circuits. --- ## [Quadratic Unconstrained Binary Optimization (QUBO) Demo](https://discuss.pennylane.ai/t/quadratic-unconstrained-binary-optimization-qubo-demo/7339)
**Author:** [@CatalinaAlbornoz](https://discuss.pennylane.ai/u/CatalinaAlbornoz)\ **Replies:** 0\ **Last updated:** [October 17, 2024, 7:43pm UTC](https://discuss.pennylane.ai/t/quadratic-unconstrained-binary-optimization-qubo-demo/7339 "2024-10-17T19:43:14Z")
Use this topic for questions related to the PennyLane Demo on Quadratic Unconstrained Binary Optimization (QUBO). --- ## [Basic tutorial: qubit rotation](https://discuss.pennylane.ai/t/basic-tutorial-qubit-rotation/7338)
**Author:** [@CatalinaAlbornoz](https://discuss.pennylane.ai/u/CatalinaAlbornoz)\ **Replies:** 0\ **Last updated:** [October 17, 2024, 7:35pm UTC](https://discuss.pennylane.ai/t/basic-tutorial-qubit-rotation/7338 "2024-10-17T19:35:26Z")
Use this topic for questions related to the PennyLane Demo on qubit rotation. --- ## [Photonic quantum computers Demo](https://discuss.pennylane.ai/t/photonic-quantum-computers-demo/7335)
**Author:** [@CatalinaAlbornoz](https://discuss.pennylane.ai/u/CatalinaAlbornoz)\ **Replies:** 0\ **Last updated:** [October 17, 2024, 7:24pm UTC](https://discuss.pennylane.ai/t/photonic-quantum-computers-demo/7335 "2024-10-17T19:24:14Z")
Use this topic for questions related to the PennyLane Demo on Photonic quantum computers. --- ## [Understanding the Haar measure Demo](https://discuss.pennylane.ai/t/understanding-the-haar-measure-demo/7334)
**Author:** [@CatalinaAlbornoz](https://discuss.pennylane.ai/u/CatalinaAlbornoz)\ **Replies:** 0\ **Last updated:** [October 17, 2024, 7:18pm UTC](https://discuss.pennylane.ai/t/understanding-the-haar-measure-demo/7334 "2024-10-17T19:18:10Z")
Use this topic for questions related to the PennyLane Demo on Understanding the Haar measure! --- ## [Can quantum transfer learning be used for multi-classification？](https://discuss.pennylane.ai/t/can-quantum-transfer-learning-be-used-for-multi-classification/3963)
**Author:** [@sunny\_chan](https://discuss.pennylane.ai/u/sunny_chan)\ **Replies:** 3\ **Last updated:** [September 26, 2024, 10:50pm UTC](https://discuss.pennylane.ai/t/can-quantum-transfer-learning-be-used-for-multi-classification/3963 "2024-09-26T22:50:29Z")
I tested the quantum transfer learning code provided in the demo, and applied it to my own data for a three-classification task. The results show that quantum transfer learning quantum transfer learning seems to classify… --- ## [QAOA and optimization](https://discuss.pennylane.ai/t/qaoa-and-optimization/5188)
**Author:** [@I\_love\_quantum](https://discuss.pennylane.ai/u/I_love_quantum)\ **Replies:** 6\ **Last updated:** [September 25, 2024, 5:51pm UTC](https://discuss.pennylane.ai/t/qaoa-and-optimization/5188 "2024-09-25T17:51:10Z")
Hi all, I’ve been learning a lot about quantum and I really love it. Especially everything we can do with it! I think it can help with the vehicle routing problem. And so many other real applications. Optimization is my… --- ## [Generalize the QML demo of "function fitting using quantum signal processing"](https://discuss.pennylane.ai/t/generalize-the-qml-demo-of-function-fitting-using-quantum-signal-processing/5190)
**Author:** [@Daniel\_Wang](https://discuss.pennylane.ai/u/Daniel_Wang)\ **Replies:** 3\ **Last updated:** [September 20, 2024, 8:03pm UTC](https://discuss.pennylane.ai/t/generalize-the-qml-demo-of-function-fitting-using-quantum-signal-processing/5190 "2024-09-20T20:03:38Z")
Hello! Thank you for giving such interesting demos! I had a question about the QML demo of function fitting using quantum signal processing. I notice that the demo is just used for 1D, but are there related demos used f… --- ## [VQLS value error when implementing U to obtain b](https://discuss.pennylane.ai/t/vqls-value-error-when-implementing-u-to-obtain-b/5200)
**Author:** [@adilet\_akimshe](https://discuss.pennylane.ai/u/adilet_akimshe)\ **Replies:** 1\ **Last updated:** [September 18, 2024, 1:19am UTC](https://discuss.pennylane.ai/t/vqls-value-error-when-implementing-u-to-obtain-b/5200 "2024-09-18T01:19:15Z")
I was trying to implement my own b in the demo provided by the link below. I create the same b that was used in the demo for VQLS, though contstruct it in a slightly different way. The unitary I create is indeed unitary … --- ## [Questions on QGAN tutorial](https://discuss.pennylane.ai/t/questions-on-qgan-tutorial/2607)
**Author:** [@mini](https://discuss.pennylane.ai/u/mini)\ **Replies:** 6\ **Last updated:** [August 30, 2024, 3:26pm UTC](https://discuss.pennylane.ai/t/questions-on-qgan-tutorial/2607 "2024-08-30T15:26:05Z")
Hello, I have some questions about Quantum GAN. For point (3) Non-Linear Transform, I did not know why we could add the ancilla qubit to create the non-linear transformation. Another question is, don’t we lose the critic… --- ## [Classical shadows in calculating fidelity](https://discuss.pennylane.ai/t/classical-shadows-in-calculating-fidelity/3727)
**Author:** [@DonaldTrump](https://discuss.pennylane.ai/u/DonaldTrump)\ **Replies:** 1\ **Last updated:** [November 27, 2023, 7:30pm UTC](https://discuss.pennylane.ai/t/classical-shadows-in-calculating-fidelity/3727 "2023-11-27T19:30:38Z")
I’m learning classical shadows and I’ve successfully reconstructed 10 qubits GHZ state.Now I have a shadow state,and I wanna calculate the fidelity between shadow state and standard 10 qubits GHZ state.I wanna know the e… --- ## [Variational Classifier Demo: Question on padding](https://discuss.pennylane.ai/t/variational-classifier-demo-question-on-padding/3367)
**Author:** [@Sarvapriya\_Tripathi](https://discuss.pennylane.ai/u/Sarvapriya_Tripathi)\ **Replies:** 4\ **Last updated:** [August 31, 2023, 4:17pm UTC](https://discuss.pennylane.ai/t/variational-classifier-demo-question-on-padding/3367 "2023-08-31T16:17:11Z")
In the variational classifier demo why was the 2 feature data from IRIS padded to make 4 features before calculating the angles? --- ## [Understanding Grover](https://discuss.pennylane.ai/t/understanding-grover/3340)
**Author:** [@epothos](https://discuss.pennylane.ai/u/epothos)\ **Replies:** 14\ **Last updated:** [August 30, 2023, 8:45pm UTC](https://discuss.pennylane.ai/t/understanding-grover/3340 "2023-08-30T20:45:22Z")
Very much enjoyed @Guillermo\_Alonso tutorial on Grover. I am interested in two questions. First, where exactly is the quantum resource. Second, does the oracle need to check all entries anyway (to decide for which one am… --- ## [Kernel based training demonstration](https://discuss.pennylane.ai/t/kernel-based-training-demonstration/1017)
**Author:** [@kabirkhanna85](https://discuss.pennylane.ai/u/kabirkhanna85)\ **Replies:** 2\ **Last updated:** [May 4, 2021, 12:39pm UTC](https://discuss.pennylane.ai/t/kernel-based-training-demonstration/1017 "2021-05-04T12:39:48Z")
I am new to kernel methods and so I was trying to run the demonstration on my local notebook. Here’s the code: import numpy as np import torch from torch.nn.functional import relu from sklearn.svm import SVC from sklea… [Previous page](https://discuss.pennylane.ai/c/demos/25.md)