6–11 Dec 2026
Stellenbosch University
Africa/Johannesburg timezone

Quantum Tilted Loss in Variational Quantum Optimization: Theory and Applications

Not scheduled
20m
Jan Mouton Learning Centre (Stellenbosch University)

Jan Mouton Learning Centre

Stellenbosch University

Poster

Speakers

Dr Josep Lumbreras (Nanyang Quantum Hub, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore) Yixian Qiu (Centre for Quantum Technologies, National University of Singapore, Singapore)

Description

Variational quantum algorithms are promising for near-term quantum devices, but their optimization is hindered by barren plateaus and finite-shot noise. We introduce the Quantum Tilted Loss (QTL), a one-parameter nonlinear objective obtained by exponentially tilting measurement outcomes of an observable. The tilt selects the relevant spectral region: zero tilt recovers the expectation value, while negative tilt emphasizes low-energy outcomes. QTL preserves global minimizers, connects to CVaR and Gibbs/free-energy losses, and admits finite-shot estimators for diagonal Hamiltonians. Analytic benchmarks and QAOA MaxCut simulations show that moderate or scheduled tilts improve trainability, whereas excessive tilting becomes statistically costly.

Topic Quantum-enhanced robustness in machine learning models
Additional Topic Quantum variational circuits and their applications

Author

Yixian Qiu (Centre for Quantum Technologies, National University of Singapore, Singapore)

Co-authors

Dr Josep Lumbreras (Nanyang Quantum Hub, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore) Prof. Patrick Rebentrost (Centre for Quantum Technologies, National University of Singapore, Singapore) Mr Xiufan Li (Centre for Quantum Technologies, National University of Singapore, Singapore)

Presentation materials