Non-Orthogonal Amplitude Amplification for Hybrid CV-DV Quantum Processors

@misc{liu2026nonorthogonal,
  title = {{Non-Orthogonal Amplitude Amplification for Hybrid CV-DV Quantum Processors}},
  author = {Jiyuan Liu and Joel Bierman and Yuan Liu},
  howpublished = {arXiv},
  year = {2026},
  month = oct,
  doi = {10.48550/arxiv.2610.09353},
  eprint = {2610.09353},
  archivePrefix = {arXiv},
  url = {https://arxiv.org/abs/2610.09353},
}

TY  - UNPB
TI  - Non-Orthogonal Amplitude Amplification for Hybrid CV-DV Quantum Processors
AU  - Jiyuan Liu
AU  - Joel Bierman
AU  - Yuan Liu
PY  - 2026
DA  - 2026/10/07
PB  - arXiv
DO  - 10.48550/arxiv.2610.09353
UR  - https://arxiv.org/abs/2610.09353
AB  - We introduce a non-orthogonal amplitude amplification (NOAA) method for hybrid continuous-variable- discrete-variable (CV-DV) quantum processors, where the available CV-assisted projector is not perfectly se- lective for the target state. We establish a bound on the achievable target-state fidelity, which is determined by the initial target-state amplitude and the selectivity of the accessible reflection operator. This bound limits the performance of NOAA in hybrid CV-DV systems. To mitigate this limitation, we propose using a squeezed CV ancilla to reduce the overlap between relevant CV states and a hybrid quantum signal processing (HQSP) filter to suppress errors arising from imperfect knowledge of the target eigenenergy. Numerical simulations show that, for small initial target-state amplitudes, our protocol achieves higher fidelity and efficiency than the repeat-until-success (RUS) method despite the presence of non-orthogonality. For large initial amplitudes, RUS is already efficient, and amplitude amplification provides little additional advantage.
ER  -