Leakage suppression for high-fidelity exchange gates and quantum simulation in superconducting circuits
Year: 2026
Type: preprint
Abstract: Parametric frequency modulation makes superconducting interactions programmable for quantum gates and quantum simulation. Leakage into higher transmon levels and coupler modes degrades gate fidelity and takes simulated dynamics outside the intended state space. Simple pulse shaping reduces off-resonant excitation, while strong coupling and short pulses demand simultaneous control of multiple leakage pathways. Controlling these pathways across individual exchange operations and simultaneous couplings is essential for fast gates and faithful programmable dynamics. We introduce parametric derivative removal by adiabatic gate (PDRAG), combining derivative shaping and finite-pulse calibration for qubit and coupler modulation. At an interqubit coupling of $g/2π=100$ MHz, simulations demonstrate 13-ns exchange operations, approaching the timescale of fast single-qubit gates. Combined with calibrated phase accumulation, these pulses realize a two-parameter fSim gate family with infidelity below $1.8\times10^{-7}$. For quantum simulation, PDRAG suppresses leakage and improves fidelity in continuous and digital Floquet simulations of Su--Schrieffer--Heeger chains. Floquet analysis identifies finite-pulse return interference as the calibration mechanism; realistic-circuit transfer preserves suppression. PDRAG establishes a unified framework spanning quantum gates and quantum simulation.
Source: arXiv (Cornell University)
Authors: Li, Yiwen, Tan, Xinsheng, Yu, Yang
Language: English
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7214899561