A 2048-spin bulk acoustic wave Ising machine for number partitioning and Sudoku
Abstract
Optical coherent Ising machines based on time-multiplexing have demonstrated significant progress in terms of connectivity and spin scalability. However, they are constrained by large physical footprints, high power consumption, poor thermal stability, and high cost. Here, we present a time-multiplexed Ising machine leveraging propagating wave packets in solid-state delay lines at microwave frequencies, enabling thermally stable, robust, low-power, tabletop, and affordable design. We use two serially connected 20.5 MHz, 707 microseconds bulk acoustic wave delay lines supporting 2,048 spins. Our design provides all-to-all connectivity with 15-bit coupling resolution and finds approximate MAX-CUT solutions in 341 ms, potentially scalable to sub-ms by using higher frequency delay lines. Additionally, we demonstrate solutions to number partitioning and Sudoku problems. Compared with state-of-the-art Coherent Ising machines, our machine exhibits four orders of magnitude higher thermal stability. Against the simulated bifurcation algorithm, our design achieves comparable results on the MAX-CUT problem, while outperforming it on the more complex number-partitioning and Sudoku problems.
Versions
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BibTeX
@misc{vadde20262048spin,
title = {{A 2048-spin bulk acoustic wave Ising machine for number partitioning and Sudoku}},
author = {Venkatesh Vadde and Roman Ovcharov and Victor H. González and Roman Khymyn and Artem Litvinenko and Johan Åkerman},
howpublished = {arXiv},
year = {2026},
month = jul,
doi = {10.48550/arxiv.2607.02112},
eprint = {2607.02112},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2607.02112},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - A 2048-spin bulk acoustic wave Ising machine for number partitioning and Sudoku
AU - Venkatesh Vadde
AU - Roman Ovcharov
AU - Victor H. González
AU - Roman Khymyn
AU - Artem Litvinenko
AU - Johan Åkerman
PY - 2026
DA - 2026/07/02
PB - arXiv
DO - 10.48550/arxiv.2607.02112
UR - https://arxiv.org/abs/2607.02112
AB - Optical coherent Ising machines based on time-multiplexing have demonstrated significant progress in terms of connectivity and spin scalability. However, they are constrained by large physical footprints, high power consumption, poor thermal stability, and high cost. Here, we present a time-multiplexed Ising machine leveraging propagating wave packets in solid-state delay lines at microwave frequencies, enabling thermally stable, robust, low-power, tabletop, and affordable design. We use two serially connected 20.5 MHz, 707 microseconds bulk acoustic wave delay lines supporting 2,048 spins. Our design provides all-to-all connectivity with 15-bit coupling resolution and finds approximate MAX-CUT solutions in 341 ms, potentially scalable to sub-ms by using higher frequency delay lines. Additionally, we demonstrate solutions to number partitioning and Sudoku problems. Compared with state-of-the-art Coherent Ising machines, our machine exhibits four orders of magnitude higher thermal stability. Against the simulated bifurcation algorithm, our design achieves comparable results on the MAX-CUT problem, while outperforming it on the more complex number-partitioning and Sudoku problems.
ER -