Protected quantum gates using qubit doublons in dynamical optical lattices.

Area of Science:

• Quantum computing
• Atomic physics
• Quantum information science

Background:

• Neutral atoms in optical lattices are a promising platform for quantum computing.
• Collisional gates are a stable mechanism for quantum logic, but require fine-tuning.
• Previous methods obscured quantum geometry and statistics, hindering robust operations.

Purpose of the Study:

• To propose and demonstrate a purely geometric two-qubit SWAP gate.
• To leverage quantum geometry and fermionic statistics for intrinsically robust quantum logic.
• To develop a new model for fault-tolerant quantum computation.

Main Methods:

• Experimentally demonstrated a geometric two-qubit SWAP gate using fermionic atoms in a dynamical optical lattice.
• Utilized transient population of qubit doublon states.
• Leveraged fermionic exchange anti-symmetry for two-particle quantum holonomy.

Main Results:

• Achieved a loss-corrected amplitude fidelity of 99.91(7)% across over 17,000 atom pairs.
• Demonstrated a gate mechanism intrinsically protected against potential fluctuations and inhomogeneities.
• Showcased resilience reinforced by time-reversal and chiral symmetries.

Conclusions:

• The proposed geometric gate offers intrinsic protection against errors, enhancing fault tolerance.
• This approach transforms fundamental symmetries into a resource for robust quantum computation.
• Combined with topological pumping, this paves the way for large-scale, highly connected quantum processors.