A Fermionic Orbital Quantum Simulator with Local Digital Tunnelling Gates

Introduction

Fermions are ubiquitous in nature, and the study of fermionic systems with strong correlations lies at the center of many fundamental and relevant problems in modern physics and chemistry. Any microscopic simulation not only needs to treat exponentially large Hilbert spaces but also has to accurately represent the fermionic exchange statistics.

Challenges in Classical Methods

However, classical numerical methods suffer from a well-known sign problem, and conventional gate-based quantum computers employ distinguishable spin-1/2 degrees of freedom, which requires a significant algorithmic overhead for handling fermionic systems.

Overview of FOrbQ

FOrbQ will be the first quantum processor with digital gates that addresses the anticommutation on the hardware level by using fermionic neutral atoms. Drawing from my ten-year experience with optical superlattices and quantum gas microscopes, I will develop stable, programmable tunneling and exchange gates in an optical lattice with full local control over the tunneling rates.

Innovative Approach

With tunable collisions of atoms and a rapid cycle time, FOrbQ introduces a digital bottom-up approach for the simulation of strongly correlated Fermi systems. By directly controlling the coupling between fermionic spin orbitals, FOrbQ will implement local 2D Hamiltonians efficiently without the cumbersome fermion-to-spin qubit mapping.

Applications

I will apply the novel hardware to open questions of hole pairing and exotic superconductivity in the Hubbard model, as well as perform the first simulations of molecules. Inherently, the atoms implement particle-number conservation and spin symmetries, making FOrbQ a powerful platform for electron simulations from multi-band Hubbard models to quantum chemistry.

Conclusion

FOrbQ combines well-tested robust technologies of ultracold atoms with concepts from quantum computing to create the first fermionic quantum computer and outline a clear path towards a practical quantum advantage for the simulation of electrons.