Optimizing two-qubit gates for ultracold fermions in optical lattices

TL;DR

This paper presents optimized collision-based two-qubit gates for ultracold fermionic Lithium atoms in optical lattices, achieving high fidelity by accounting for momentum-dependent interactions.

Contribution

It introduces a novel optimization of collision gates that captures momentum dependence, extending beyond traditional Fermi-Hubbard models.

Findings

High-fidelity gates achieved through laser amplitude control.

Momentum dependence enhances interaction strength for atoms in separate subwells.

Tailored gate optimization possible for quantum chemistry and simulation applications.

Abstract

Ultracold neutral atoms in optical lattices are a promising platform for simulating the behavior of complex materials and implementing quantum gates. We optimize collision gates for fermionic Lithium atoms confined in a double-well potential, controlling the laser amplitude and keeping its relative phase constant. We obtain high-fidelity gates based on a one-dimensional confinement simulation. Our approach extends beyond earlier Fermi-Hubbard simulations by capturing a momentum dependence in the interaction energy. This leads to a higher interaction strength when atoms begin in separate subwells compared to the same subwell. This momentum dependence might limit the gate fidelity under realistic experimental conditions, but also enables tailored applications in quantum chemistry and quantum simulation by optimizing gates for each of these cases separately.