Continuous Variable Quantum MNIST Classifiers—Classical-Quantum Hybrid Quantum Neural Networks

In this paper, classical and continuous variable (CV) quantum neural network hybrid multi-classifiers are presented using the MNIST dataset. Currently available classifiers can classify only up to two classes. The proposed architecture allows networks to classify classes up to nm classes, where n represents cutoff dimension and m the number of qumodes on photonic quantum computers. The combination of cutoff dimension and probability measurement method in the CV model allows a quantum circuit to produce output vectors of size nm. They are then interpreted as one-hot encoded labels, padded with nm - 10 zeros. The total of seven different classifiers is built using 2, 3, …, 6, and 8-qumodes on photonic quantum computing simulators, based on the binary classifier architecture proposed in “Continuous variable quantum neural networks” [1]. They are composed of a classical feed-forward neural network, a quantum data encoding circuit, and a CV quantum neural network circuit. On a truncated MNIST dataset of 600 samples, a 4-qumode hybrid classifier achieves 100% training accuracy.

Quantum classifier with parameterized quantum circuit based on the isolated quantum system

It is a critical challenge for quantum machine learning to classify the datasets accurately.This article develops a quantum classifier based on the isolated quantum system(QC-IQS)to classify nonlinear and multidimensional datasets.First,a model of QC-IQS is presented by creating parameterized quantum circuits(PQCs)based on the decomposing of unitary operators with the Hamiltonian in the isolated quantum system.Then,a parameterized quantum classification algorithm(QCA)is designed to calculate the classification results by updating the loss function until it converges.Finally,the experiments on nonlinear random number datasets and Iris datasets are designed to demonstrate that the QC-IQS model can handle and generate accurate classification results on different kinds of datasets.The experimental results reveal that the QC-IQS is adaptive and learnable to handle different types of data.Moreover,QC-IQS compensates the issue that the accuracy of previous quantum classifiers declines when dealing with diverse datasets.It promotes the process of novel data processing with quantum machine learning and has the potential for more comprehensive applications in the future.