Eigen-SNAP gate for photonic qubits in a cavity-transmon system
Year: 2026
Type: article
Abstract: In the pursuit of robust quantum computing, we put forth a platform based on photonic qubits in a circuit-QED environment. Specifically, we propose a versatile two-qubit gate based on two cavities coupled via a transmon, constituting a selective number-dependent phase gate operating on the in-phase eigenmodes of the two cavities, the Eigen-SNAP gate. This gate natively operates in the dispersive coupling regime of the cavities and the transmon, and operates by driving the transmon externally, to imprint desired phases on the number states. As an example for the utility of the Eigen-SNAP gate, we implement a SWAP gate on a system of two logical bosonic qubits encoded in the cavities. Further, we use numerical optimization to determine the optimal implementation of the SWAP . We find that the fidelities of these optimal protocols are only limited by the coherence times of the system's components. These findings pave the way to continuous-variable quantum computing in cavity-transmon systems.
Source: Physical Review Research
DOI: 10.1103/2ks4-p82h
Authors: Marcus Meschede, Ludwig Mathey
Institutions: Universität Hamburg, Hamburg Centre for Ultrafast Imaging
Language: English
Subfield: Artificial Intelligence
Field: Computer Science
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $2,625
OpenAlex ID: W4415102366