Robustness of generalized controlled-not gates against static errors in quantum-dot systems
Phys. Rev. A 114, 032620 – Published 24 September, 2026
DOI: https://doi.org/10.1103/cq57-k2vx
Abstract
We propose a method for realizing a high-fidelity and robust controlled-not gate in a Si double-quantum-dot system. The Hamiltonian of the system is first reduced to a block-diagonal form, dividing it into two individual subsystems. Given the interdependence of certain parameters between these subsystems, we develop two techniques, detuning modulation and magnetic-field rotation, to perform a robust identity operation in one subsystem and a reliable not gate in the other subsystem. Numerical results validate the feasibility of this methodology, demonstrating that the controlled-not gate we design still maintains very high fidelity over a relatively wide range of pulse duration deviations. Furthermore, the pulse shape we adopt is a common square wave, which is easy to obtain in practice. This work can provide a general framework for the realization of reliable quantum computations in silicon-based quantum-dot systems.
