INQA

An International Network on Quantum Annealing

The International Network on Quantum Annealing (INQA) will for the first time establish a mechanism by which four global collaborations come together to share technical and intellectual know-how and critically analyse developments in theoretical and experimental research in quantum annealing.

Upcoming Seminars

December 3 2024 | 17:00 UTC | Ernesto Acosta | University of Granada 

Adiabatic training for Variational Quantum Algorithms

On this talk we present a new hybrid Quantum Machine Learning model (QML) composed of elements: a classical computer in charge of the data preparation and interpretation; a Gate-based Quantum Computer running the Variational Quantum Algorithm (VQA) representing a Quantum Neural Network (QNN); and an adiabatic Quantum Computer where the optimization function is executed to find the best parameters for the VQA. As of the present moment the majority of VQAs are being trained using gradient-based classical optimizers having to deal with the barren-plateau effect1. Some gradient-free classical approaches such as Evolutionary Algorithms have also been proposed to overcome this effect2. However, adiabatic quantum models have not been defined to train VQAs. A quick review of Artificial Neural Networks and Variational Quantum Algorithms concepts is presented, along with the description of barren-plateau effect in relation to vanishing gradients. Then we will describe the proposed adiabatic training model comparing the obtained results against the classical gradient-based algorithms, showing the feasibility of integration for gate-based and adiabatic quantum computing models. We will end up with some highlights on the current phase of research towards iterative and multithreaded adiabatic training.

 

December 10 2024 | 09:00 UTC | Shohei Watabe |  Shibaura Institute of Technology

Title: Penalty-Based and Constrained Quantum Annealing under Noise

Abstract: Optimization problems with constraints are a critical focus in both classical and quantum computing. Penalty-based quantum annealing (PQA) is a widely used approach that transforms constrained problems into unconstrained ones by introducing penalties for constraint violations. In contrast, constrained quantum annealing (CQA) offers a hardware-efficient alternative [1]. CQA initializes the quantum state to satisfy the constraints and employs a driver Hamiltonian designed to commute with the constraint operators, ensuring the state remains within the constraint-satisfying subspace throughout the annealing process. Despite its potential, a systematic performance comparison between PQA and CQA has been lacking. This talk presents a comparative study of PQA and CQA, evaluating their performance both in ideal and noisy environments [2].[1] I. Hen and F. M. Spedalieri, Phys. Rev. Applied 5, 034007 (2016). [2] R. Igata, M. I, Y. Seki, Y. Mizuno, and S. Watabe, arXiv:2410.17528

Visit past seminars to view a list of all of our past seminars and their abstracts.

If you miss any of our live seminars you can watch our previous sessions on our YouTube Channel.

About INQA

The INQA network unifies the research activities of major global collaborations in quantum annealing in North America, Japan, the European Union and the United Kingdom.

By hosting weekly on-line seminars and annual international conferences and by funding exchange visits, the INQA network will address the key topics which will enable quantum annealing to move towards a true quantum scaling advantage over classical approaches to NP-hard computational problems. 

The topics INQA will focus on include:

• Exploiting quantum coherence
• Extending the order and degree of qubit interactions
• Strategies for error correction 
• Exploiting diabaticity and non-stoquasticity in a systematic way

The network will be led by Professor Paul Warburton of UCL, who is a co-investigator in the UK’s Quantum Computation and Simulation (QCS) Hub and in the recently-announced QEVEC project. He was also previously a co-investigator in the US-led QEO and QAFS collaborations.

Members of the management board include: 

• Prof Paul Warburton (UCL, UK)
• Dr Pol Forn-Díaz (IFAE, Spain)
• Dr Shiro Kawabata (AIST, Japan)
• Prof Viv Kendon (University of Strathclyde, UK)
• Dr Jamie Kerman (MIT Lincoln Lab, USA)

INQA is supported by a International Network Grant from the UK Engineering and Physical Sciences Research Council.