PPD-NQCC seminar: What Should Quantum Supercomputers Compute? From Quantum-Native Algorithms to Scientific Discovery—and Back

by Prof. Harry Buhrman (Quantinuum)

Wednesday 23 Sept 2026, 11:30 → 12:30 Europe/London

R61 CR03 (RAL)

Abstract: 

Which problems can quantum computers solve faster than classical computers, and where can this advantage lead to useful scientific discoveries? Worst-case complexity provides essential guidance, but practical progress also requires identifying specific instances and physical regimes where quantum algorithms succeed and classical methods struggle.

In this talk, I will discuss quantum heuristics and the search for “queasy instances”: problems that are quantum-easy but classically hard. I will explore two complementary approaches. A bottom-up approach starts with a distinct quantum capability, validates it on hardware, and seeks useful applications. A top-down approach starts with a scientific question and develops the quantum algorithms and computational workflow needed to address it.

Three examples illustrate the interplay between these approaches: complement sampling, with provable quantum advantages in sample complexity; quantum topological data analysis, using Laplacian moments to extract structural features for machine learning and fraud detection; and simulations of interacting-electron dynamics aimed at understanding light-induced superconductivity. Drawing on theoretical results, hardware experiments, and classical benchmarks, I will distinguish demonstrated capabilities from opportunities for future advantage. The central goal is to connect advances in quantum hardware to scientific discovery, building a foundation for practical and industrial applications.

 

About Speaker:

Harry Buhrman is Chief Scientist for Quantum Algorithms & Innovation at Quantinuum and Professor of Algorithms, Complexity Theory, and Quantum Computing at the University of Amsterdam. He is the founding director of QuSoft, the Dutch research centre for quantum software, which he co-founded in 2015, and was elected to the Royal Netherlands Academy of Arts and Sciences in 2020.

A pioneer of quantum computing research, Buhrman established the first quantum computing group in the Netherlands in the late 1990s, among the earliest worldwide to focus on quantum information processing. His work has made foundational contributions to quantum algorithms, communication complexity, and computational complexity theory. He helped demonstrate that quantum resources can provide exponential advantages in communication tasks and co-developed key methods for understanding both the power and limitations of quantum computers.

He has received a prestigious Vici grant and serves on several international scientific advisory boards.