variational circuit
Quantum Temporal Fusion Transformer
Barik, Krishnakanta, Paul, Goutam
The \textit{Temporal Fusion Transformer} (TFT), proposed by Lim \textit{et al.}, published in \textit{International Journal of Forecasting} (2021), is a state-of-the-art attention-based deep neural network architecture specifically designed for multi-horizon time series forecasting. It has demonstrated significant performance improvements over existing benchmarks. In this work, we introduce the Quantum Temporal Fusion Transformer (QTFT), a quantum-enhanced hybrid quantum-classical architecture that extends the capabilities of the classical TFT framework. The core idea of this work is inspired by the foundation studies, \textit{The Power of Quantum Neural Networks} by Amira Abbas \textit{et al.} and \textit{Quantum Vision Transformers} by El Amine Cherrat \textit{et al.}, published in \textit{ Nature Computational Science} (2021) and \textit{Quantum} (2024), respectively. A key advantage of our approach lies in its foundation on a variational quantum algorithm, enabling implementation on current noisy intermediate-scale quantum (NISQ) devices without strict requirements on the number of qubits or circuit depth. Our results demonstrate that QTFT is successfully trained on the forecasting datasets and is capable of accurately predicting future values. In particular, our experimental results on two different datasets display that the model outperforms its classical counterpart in terms of both training and test loss. These results indicate the prospect of using quantum computing to boost deep learning architectures in complex machine learning tasks.
Sub-universal variational circuits for combinatorial optimization problems
Weitz, Gal, Pira, Lirandë, Ferrie, Chris, Combes, Joshua
Quantum variational circuits have gained significant attention due to their applications in the quantum approximate optimization algorithm and quantum machine learning research. This work introduces a novel class of classical probabilistic circuits designed for generating approximate solutions to combinatorial optimization problems constructed using two-bit stochastic matrices. Through a numerical study, we investigate the performance of our proposed variational circuits in solving the Max-Cut problem on various graphs of increasing sizes. Our classical algorithm demonstrates improved performance for several graph types to the quantum approximate optimization algorithm. Our findings suggest that evaluating the performance of quantum variational circuits against variational circuits with sub-universal gate sets is a valuable benchmark for identifying areas where quantum variational circuits can excel.
Multilingual Machine Translation with Quantum Encoder Decoder Attention-based Convolutional Variational Circuits
Dikshit, Subrit, Tiwari, Ritu, Jain, Priyank
In the 2000s, artificial intelligence and deep learning - based systems became prevalent and took over the world by storm . Many modern multilingual state - of - the - art [ 1 ] networks and cloud - based translation services like Google Translate, Microsoft Translator, ChatGPT [ 2 ], DeepSeek [ 3 ] emerged and became available during this era . These Multilingual Large Language Networks are architected around Gated Recurrent Unit Networks ( GRU) [ 4 ], Long Short - Term Memory ( LSTM) [ 5 ], Bidirectional Encoder Representations from Transformers ( BERT) [ 6 ], Generative pre - trained transformer ( GPT) [ 7 ], Text - to - Text Transfer Transformer ( T5) [ 8 ] and similar attention - based transformers [ 9 ] networks with finer and improve d amendments to architectures. W hile m ost academicians, researchers, and organisations focused on these classical computing realm aspects and less emphasis was put on multilingual machine tr a nslation in the quantum computing realm . S ome practitioners and scholars who emphasis ed quantum computing for machine tr a nslation and their associated works are discussed in the Related Works section later. However, these researches under - u tilize d simulat ion and execution on quantum computing hardware along with under - exploit ing the novel perceptions of quantum convolution [ 10 ], quantum pooling [ 11 ], quantum variational circuit [ 12 ] and quantum attention [ 13 ] as quantum - based software amendments that are studie d, demonstrate d and stunned as shortcomings in QEDACVC system .
Toward Automated Quantum Variational Machine Learning
In this work, we address the problem of automating quantum variational machine learning. We develop a multi-locality parallelizable search algorithm, called MUSE, to find the initial points and the sets of parameters that achieve the best performance for quantum variational circuit learning. Simulations with five real-world classification datasets indicate that on average, MUSE improves the detection accuracy of quantum variational classifiers 2.3 times with respect to the observed lowest scores. Moreover, when applied to two real-world regression datasets, MUSE improves the quality of the predictions from negative coefficients of determination to positive ones. Furthermore, the classification and regression scores of the quantum variational models trained with MUSE are on par with the classical counterparts.
Hierarchical Learning for Quantum ML: Novel Training Technique for Large-Scale Variational Quantum Circuits
Gharibyan, Hrant, Su, Vincent, Tepanyan, Hayk
We present hierarchical learning, a novel variational architecture for efficient training of large-scale variational quantum circuits. We test and benchmark our technique for distribution loading with quantum circuit born machines (QCBMs). With QCBMs, probability distributions are loaded into the squared amplitudes of computational basis vectors represented by bitstrings. Our key insight is to take advantage of the fact that the most significant (qu)bits have a greater effect on the final distribution and can be learned first. One can think of it as a generalization of layerwise learning, where some parameters of the variational circuit are learned first to prevent the phenomena of barren plateaus. We briefly review adjoint methods for computing the gradient, in particular for loss functions that are not expectation values of observables. We first compare the role of connectivity in the variational ansatz for the task of loading a Gaussian distribution on nine qubits, finding that 2D connectivity greatly outperforms qubits arranged on a line. Based on our observations, we then implement this strategy on large-scale numerical experiments with GPUs, training a QCBM to reproduce a 3-dimensional multivariate Gaussian distribution on 27 qubits up to $\sim4\%$ total variation distance. Though barren plateau arguments do not strictly apply here due to the objective function not being tied to an observable, this is to our knowledge the first practical demonstration of variational learning on large numbers of qubits. We also demonstrate hierarchical learning as a resource-efficient way to load distributions for existing quantum hardware (IBM's 7 and 27 qubit devices) in tandem with Fire Opal optimizations.
Can Feature Engineering Help Quantum Machine Learning for Malware Detection?
Liu, Ran, Eren, Maksim, Nicholas, Charles
With the increasing number and sophistication of malware attacks, malware detection systems based on machine learning (ML) grow in importance. At the same time, many popular ML models used in malware classification are supervised solutions. These supervised classifiers often do not generalize well to novel malware. Therefore, they need to be re-trained frequently to detect new malware specimens, which can be time-consuming. Our work addresses this problem in a hybrid framework of theoretical Quantum ML, combined with feature selection strategies to reduce the data size and malware classifier training time. The preliminary results show that VQC with XGBoost selected features can get a 78.91% test accuracy on the simulator. The average accuracy for the model trained using the features selected with XGBoost was 74% (+- 11.35%) on the IBM 5 qubits machines.
Quantum Text Classifier -- A Synchronistic Approach Towards Classical and Quantum Machine Learning
Santi, Dr. Prabhat, Mishra, Kamakhya, Mohanty, Sibabrata
Although it will be a while before a practical quantum computer is available, there is no need to hold off. Methods and algorithms are being developed to demonstrate the feasibility of running machine learning (ML) pipelines in QC (Quantum Computing). There is a lot of ongoing work on general QML (Quantum Machine Learning) algorithms and applications. However, a working model or pipeline for a text classifier using quantum algorithms isn't available. This paper introduces quantum machine learning w.r.t text classification to readers of classical machine learning. It begins with a brief description of quantum computing and basic quantum algorithms, with an emphasis on building text classification pipelines. A new approach is introduced to implement an end-to-end text classification framework (Quantum Text Classifier - QTC), where pre- and post-processing of data is performed on a classical computer, and text classification is performed using the QML algorithm. This paper also presents an implementation of the QTC framework and available quantum ML algorithms for text classification using the IBM Qiskit library and IBM backends.
Simulation of a Variational Quantum Perceptron using Grover's Algorithm
Innan, Nouhaila, Bennai, Mohamed
Recently, there has been an increasing number of studies to combine the disciplines of quantum information and machine learning, and a variety of theories to merge these fields have consistently been put forward since machine learning is under pressure due to a lack of processing power of the increased amount of data in the world, and quantum computing offers these super computational capabilities. The combination of these two fields invariably leads to a massive interest in innovative information processing mechanisms that open up a new and improved range of solutions for various domains of applications, and the first concept was the research on quantum models of neural networks; it was essentially biologically inspired, in the hope of finding explanations for brain function within the framework of quantum theory [1]. In 2013, this combination got the name quantum machine learning by Lloyd et al. [2] as a definition of an area of research that explores the combination of quantum information and ML principles. However, the development of potential quantum machine learning algorithms has made some progress; several famous classical ML algorithms already have quantum analogs, such as the quantum support vector machine (QSVM), quantum k-means clustering, quantum Boltzmann machine (QBM), and the quantum perceptron (QP) which there have been some papers that mainly overview methods and algorithms of this model. Zhou et al. [3] developed a quantum perceptron approach based on the quantum phase capable of computing the XOR function using only one neuron, then Siomau et al. [4] introduced an autonomous quantum perceptron based on calculating a set of positive valued operators and valued measurements (POVM), after that Sagheer and Zidane [5] proposed a quantum perceptron based on Siomau method capable of constructing its own set of activation operators to be applied widely in both quantum and classical applications to overcome the linearity limitation of the classical perceptron In 2018, a multidimensional input quantum perceptron (MDIQP) was proposed by Yamamoto et al. [6]; their model had an arbitrary number of inputs with different synaptic weights, being able to form large quantum artificial neural networks (QANNs).
PennyLane: Automatic differentiation of hybrid quantum-classical computations
Bergholm, Ville, Izaac, Josh, Schuld, Maria, Gogolin, Christian, Ahmed, Shahnawaz, Ajith, Vishnu, Alam, M. Sohaib, Alonso-Linaje, Guillermo, AkashNarayanan, B., Asadi, Ali, Arrazola, Juan Miguel, Azad, Utkarsh, Banning, Sam, Blank, Carsten, Bromley, Thomas R, Cordier, Benjamin A., Ceroni, Jack, Delgado, Alain, Di Matteo, Olivia, Dusko, Amintor, Garg, Tanya, Guala, Diego, Hayes, Anthony, Hill, Ryan, Ijaz, Aroosa, Isacsson, Theodor, Ittah, David, Jahangiri, Soran, Jain, Prateek, Jiang, Edward, Khandelwal, Ankit, Kottmann, Korbinian, Lang, Robert A., Lee, Christina, Loke, Thomas, Lowe, Angus, McKiernan, Keri, Meyer, Johannes Jakob, Montañez-Barrera, J. A., Moyard, Romain, Niu, Zeyue, O'Riordan, Lee James, Oud, Steven, Panigrahi, Ashish, Park, Chae-Yeun, Polatajko, Daniel, Quesada, Nicolás, Roberts, Chase, Sá, Nahum, Schoch, Isidor, Shi, Borun, Shu, Shuli, Sim, Sukin, Singh, Arshpreet, Strandberg, Ingrid, Soni, Jay, Száva, Antal, Thabet, Slimane, Vargas-Hernández, Rodrigo A., Vincent, Trevor, Vitucci, Nicola, Weber, Maurice, Wierichs, David, Wiersema, Roeland, Willmann, Moritz, Wong, Vincent, Zhang, Shaoming, Killoran, Nathan
PennyLane is a Python 3 software framework for differentiable programming of quantum computers. The library provides a unified architecture for near-term quantum computing devices, supporting both qubit and continuous-variable paradigms. PennyLane's core feature is the ability to compute gradients of variational quantum circuits in a way that is compatible with classical techniques such as backpropagation. PennyLane thus extends the automatic differentiation algorithms common in optimization and machine learning to include quantum and hybrid computations. A plugin system makes the framework compatible with any gate-based quantum simulator or hardware. We provide plugins for hardware providers including the Xanadu Cloud, Amazon Braket, and IBM Quantum, allowing PennyLane optimizations to be run on publicly accessible quantum devices. On the classical front, PennyLane interfaces with accelerated machine learning libraries such as TensorFlow, PyTorch, JAX, and Autograd. PennyLane can be used for the optimization of variational quantum eigensolvers, quantum approximate optimization, quantum machine learning models, and many other applications.
Reinforcement Learning with Quantum Variational Circuits
The development of quantum computational techniques has advanced greatly in recent years, parallel to the advancements in techniques for deep reinforcement learning. This work explores the potential for quantum computing to facilitate reinforcement learning problems. Quantum computing approaches offer important potential improvements in time and space complexity over traditional algorithms because of its ability to exploit the quantum phenomena of superposition and entanglement. Specifically, we investigate the use of quantum variational circuits, a form of quantum machine learning. We present our techniques for encoding classical data for a quantum variational circuit, we further explore pure and hybrid quantum algorithms for DQN and Double DQN. Our results indicate both hybrid and pure quantum variational circuit have the ability to solve reinforcement learning tasks with a smaller parameter space. These comparison are conducted with two OpenAI Gym environments: CartPole and Blackjack, The success of this work is indicative of a strong future relationship between quantum machine learning and deep reinforcement learning.