PsiQuantum and Boehringer Ingelheim: Fault-tolerant quantum computation of molecular observables

Most quantum chemistry research has focused on using quantum computers to calculate ground-state energies of molecules. But many other molecular properties (“observables”)—such as dipole moments or interaction strengths—are equally vital for drug discovery and materials design. Classical methods often struggle to calculate these efficiently.

In this paper, researchers from PsiQuantum, QC Ware, and Boehringer Ingelheim introduce a new quantum algorithm called Expectation Value Estimation (EVE). Designed for fault-tolerant quantum computers, EVE enables efficient estimation of molecular observables. A more advanced version, QSP-EVE, leverages quantum signal processing to dramatically reduce computational demands.

Key takeaways:

- Introduces the first fault-tolerant algorithm for estimating a broad range of molecular observables.

- QSP-EVE reduces gate counts by up to 1000x and lowers qubit requirements by 25% compared to prior methods.

- Marks a step toward practical quantum simulations of complex molecules for pharma and materials science.

While today’s quantum computers can’t yet run EVE at scale, this research shows how future fault-tolerant systems could unlock far more than energy calculations—providing richer, more accurate insights into molecular behavior for industries that rely on advanced chemistry.