2021/04/09 by Ilan Tzitrin, Takaya Matsuura, Rafael N. Alexander +5 · 2 citations
Physics and Astronomy · #quant-ph
paper · pdf · doi:10.1103/prxquantum.2.040353
published as Phys. Rev. X Quantum 2, 040353 (2021) · 15 pages, 6 figures, comments welcome; minor typos corrected and Fig. 2 updated to resolve rendering issues on some platforms
arxiv created 2021/04/09 · arxiv updated 2021/12/28
The scalability of photonic implementations of fault-tolerant quantum computing based on Gottesman-Kitaev-Preskill (GKP) qubits is injured by the requirements of inline squeezing and reconfigurability of the linear optical network. In this work we propose a topologically error-corrected architecture that does away with these elements at no cost - in fact, at an advantage - to state preparation overheads. Our computer consists of three modules: a 2D array of probabilistic sources of GKP states; a depth-four circuit of static beamsplitters, phase shifters, and single-time-step delay lines; and a 2D array of homodyne detectors. The symmetry of our proposed circuit allows us to combine the effects of finite squeezing and uniform photon loss within the noise model, resulting in more comprehensive threshold estimates. These jumps over both architectural and analytical hurdles considerably expedite the construction of a photonic quantum computer.