Henry F. Schurkus, Ph.D.

quo errat demonstrator

( |quantum> + |software> ) / sqrt(2)

science and technology

Research Publications

These are some of my personal favorites. Please find the full list here.

Linear Scaling
Random Phase Approximation

  • Henry F. Schurkus, Christian Ochsenfeld. Communication: An effective linear-scaling atomic-orbital reformulation of the random-phase approximation using a contracted double-Laplace transformation. J. Chem. Phys. 144 (3): 031101. https://doi.org/10.1063/1.4939841
  • Enabling large-scale high-precision calculations of the electronic structure of molecules, by reformulating the previously O(M8) scaling Random Phase Approximation (RPA) algorithm as O(M). M is the size of the molecule, and RPA has been shown to be more precise than HF, (hybrid) DFT, and even perturbation theory (MP2).

Quantum Error Correction
with Λ3,5 > 1

  • Google Quantum AI. Suppressing quantum errors by scaling a surface code logical qubit. Nature 614, 676–681 (2023). https://doi.org/10.1038/s41586-022-05434-1
  • First experimental demonstration of successful error correction on a quantum computer. Specifically, for the first time demonstrating that encoding a logical qubit across 49 physical qubits actually leads to less logical error than across 22 physical qubits.

Error-Free Resolution of Identity
via Particle-Hole Projection

  • Henry F. Schurkus, Arne Luenser, Christian Ochsenfeld. Communication: Almost error-free resolution-of-the-identity correlation methods by null space removal of the particle-hole interactions. J. Chem. Phys. 146 (21): 211106. https://doi.org/10.1063/1.4985085
  • Resolution of Identity (RI) is a method to express integrals over a basis set. Previously the choice of this basis was a trade-off between accuracy on computational cost. Now we are able to get perfect accuracy at marginal cost, with a clever (if I do say so myself ;)) scheme to project the equations based on physical knowledge of the system.

“Opportunity is missed by most people because it is dressed in overalls and looks like work.”

Thomas A. Edison

Inventor and Businessman