Why Quantum Computers might never work

Quick Overview

Quantum computers might never achieve the promised computational advantage because noise inherent in quantum mechanics, as argued by physicists like Gil Kalai, Robert Alicki, Gerard 't Hooft, and Tim Palmer, fundamentally limits their capability, preventing them from reliably factoring large numbers or performing complex calculations beyond what classical computers can achieve.

Key Points: A minority of physicists, including Gil Kalai, argue that quantum computers will never deliver on the promised investment returns because they cannot fundamentally work. Gil Kalai's argument suggests that the required level of precision to overcome noise (like from neutrinos or gravitational waves) is impossible for quantum computers to maintain. Robert Alicki argues that if quantum computers model noise realistically (like the Continuous Spontaneous Localization model), factoring numbers with millions of digits remains impossible. Gerard 't Hooft believes that the underlying physics preventing quantum computers from factoring large numbers implies quantum mechanics itself might not be fundamental, suggesting the collapse model is a real physical process. Tim Palmer estimates that even with significant error correction, useful quantum computation requires fewer than 1,000 logical qubits, far short of what is often advertised, and suggests that fault-tolerant quantum computation is severely limited. The video contrasts the quantum model (atom) with the non-quantum model (solar system) to illustrate the difference between classical and quantum physics rules. The sponsor, Brilliant, offers interactive courses in Math Foundations, Data Analysis, Programming & CS, and Science, with a 20% discount on annual premiums using the provided link.

Context: This video presents a skeptical viewpoint on the feasibility and projected utility of quantum computing, focusing on arguments from several theoretical physicists who question whether current quantum models can overcome fundamental physical limitations like noise and decoherence to achieve true quantum advantage over classical computers. The presenter, Sabine Hossenfelder, reviews the papers and arguments put forth by these critics, contrasting their theoretical limitations against the often optimistic claims made by quantum computing proponents.