Sufficient Condition for Universal Quantum Computation Using Bosonic Circuits
Journal article, 2024

Continuous-variable bosonic systems stand as prominent candidates for implementing quantum computational tasks. While various necessary criteria have been established to assess their resourcefulness, sufficient conditions have remained elusive. We address this gap by focusing on promoting circuits that are otherwise simulatable to computational universality. The class of simulatable, albeit non-Gaussian, circuits that we consider is composed of Gottesman-Kitaev-Preskill (GKP) states, Gaussian operations, and homodyne measurements. Based on these circuits, we first introduce a general framework for mapping a continuous-variable state into a qubit state. Subsequently, we cast existing maps into this framework, including the modular and stabilizer subsystem decompositions. By combining these findings with established results for discrete-variable systems, we formulate a sufficient condition for achieving universal quantum computation. Leveraging this, we evaluate the computational resourcefulness of a variety of states, including Gaussian states, finite-squeezing GKP states, and cat states. Furthermore, our framework reveals that both the stabilizer subsystem decomposition and the modular subsystem decomposition (of position-symmetric states) can be constructed in terms of simulatable operations. This establishes a robust resource-theoretical foundation for employing these techniques to evaluate the logical content of a generic continuous-variable state, which can be of independent interest.

Author

Cameron Calcluth

Chalmers, Microtechnology and Nanoscience (MC2), Applied Quantum Physics

Nicolas Reichel

A. Ferraro

University of Milan

Queen's University Belfast

Giulia Ferrini

Chalmers, Microtechnology and Nanoscience (MC2), Applied Quantum Physics

PRX Quantum

26913399 (eISSN)

Vol. 5 2 020337

Subject Categories

Atom and Molecular Physics and Optics

Other Physics Topics

Computer Science

DOI

10.1103/PRXQuantum.5.020337

More information

Latest update

6/7/2024 1