Journal Article

FZJ-2026-02218

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Optimizing two-qubit gates for ultracold atoms using Fermi-Hubbard models

Singh, J.FZJ* ; Reuter, J. A. P.FZJ* ; Calarco, T.FZJ* ; Motzoi, F.FZJ* ; Zeier, R.FZJ*

2025
American Physical Society College Park, Md. [u.a.]

This record in other databases:  

Please use a persistent id in citations: doi:10.1103/xqzw-m27l  doi:10.34734/FZJ-2026-02218

Abstract: Ultracold atoms trapped in optical lattices have emerged as a scalable and promising platform forquantum simulation and computation; however, gate speeds remain a significant limitation for practicalapplications. In this work, we employ quantum optimal control to design fast, collision-based two-qubitgates within a superlattice based on a Fermi-Hubbard description, reaching errors in the range 10−3 forrealistic parameters. Numerically optimizing the lattice depths and the scattering length, we effectivelymanipulate hopping and interaction strengths intrinsic to the Fermi-Hubbard model. Our results providefive times shorter gate durations by allowing for higher energy bands in the optimization, suggesting thatstandard modeling with a two-band Fermi-Hubbard model is insufficient for describing the dynamics offast gates, and we find that four to six bands are required. Additionally, we achieve nonadiabatic gatesby employing time-dependent lattice depths rather than using only fixed depths. The optimized controlpulses not only maintain high efficacy in the presence of laser-intensity and phase noise but also result innegligible interwell couplings.

---

Contributing Institute(s):

1. Quantum Control (PGI-8)

Research Program(s):

1. 5221 - Advanced Solid-State Qubits and Qubit Systems (POF4-522) (POF4-522)
2. BMBF 13N15891 - FermiQP - Fermion-Quantenprozessor (BMBF-13N15891) (BMBF-13N15891)
3. BMBF 13N16073 - MUNIQC-Atoms - Neutralatom-basierter Quantencomputer-Demonstrator (BMBF-13N16073) (BMBF-13N16073)

---

Database coverage:
; ; ; Clarivate Analytics Master Journal List ; Current Contents - Physical, Chemical and Earth Sciences ; Essential Science Indicators ; IF < 5 ; JCR ; SCOPUS ; Science Citation Index Expanded ; Web of Science Core Collection

---