Hackathon

LOQCathon Paris

Hosted by Quandela \(\vert\) Paris, France

LOQCathon was an interdisciplinary quantum hackathon focused on Linear Optical Quantum Computation (LOQC). Our challenge, “Unloqc the Energetics Properties of Molecules,” centered around implementing a Variational Quantum Eigensolver (VQE) to estimate ground state energies of molecules.

Problem-inspired ansatz used in the Variational Quantum Eigensolver implementation on a linear optical quantum computer.

Our task was to develop and optimize a VQE using Perceval, Quandela’s LOQC simulator, to compute upper bounds of the ground state energy for H₂O and LiH molecules. This involved:

  • Designing hardware-efficient ansätze compatible with LOQC architectures

  • Navigating expressivity–trainability trade-offs to avoid barren plateaus

  • Benchmarking optimizers to achieve convergence

Our solution using a problem-inspired ansatz stood out for its performance, earning us the first place.

Further information can be found in the accompanying GitHub repository.