Work

Open-system adiabatic quantum search under dephasing

Year: 2026

Type: article

Abstract: Adiabatic quantum algorithms must evolve slowly enough to suppress nonadiabatic transitions while remaining fast enough to be practical. In open systems, this trade-off is reshaped by decoherence. For Hamiltonians subject to dephasing Lindbladians, Avron . [] showed that a unique timetable exists that maximizes the fidelity with a target state. This optimal schedule is characterized by a constant tunneling rate along the adiabatic path. In this work we revisit their analysis and apply it to the adiabatic Grover search framework, obtaining closed-form expressions for the optimal evolution schedule, the minimum runtime, and the resulting achievable fidelity. Moreover, by invoking an energy-time uncertainty argument, we identify a critical dephasing threshold beyond which further noise-assisted acceleration is prohibited, showing that the apparent advantage of strong dephasing is a Zeno-type stabilization mechanism rather than a conventional algorithmic speedup over the unitary Grover search.

Source: Physical Review A

DOI: 10.1103/9q9k-92cf

Authors: Afaf El Kalai, Peter J. Eder, Christian B. Mendl

Institutions: Siemens (Germany), Technical University of Munich

Language: English

Topic: Quantum Computing Algorithms and Architecture

Subfield: Artificial Intelligence

Field: Computer Science

Domain: Physical Sciences

Open Access status: hybrid

Estimated APC paid: $2,675

Funder: Technische Universität München