2023 Fiscal Year Research-status Report
非対称スピン波干渉に基づくカラードノイズ援用低消費電力イジングマシンに関する研究
| Project/Area Number |
23KJ0605
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| Research Institution | The University of Tokyo |
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Principal Investigator |
LIAO ZHIQIANG 東京大学, 工学系研究科, 特別研究員(PD)
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| Project Period (FY) |
2023-04-25 – 2025-03-31
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| Keywords | Spin wave / Asymmetric interference / Ising machine / Low power consumption / Noise assistance |
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| Outline of Annual Research Achievements |
(1) I fabricated a 20-nm-thick 400-μm-long Y-shape spin wave interferometer (SWI) based on yttrium iron garnet. I tested different excitation frequencies under in-plan magnetic field of 20mT. The results proved that an excitation frequency of 1.8 GHz can achieve the strongest interference asymmetry.
(2) Based on experimental data, I simulated the SWI-based Ising machine. The results proved that my device can operate under conditions where the noise intensity is 2.5 times greater than its saturation spin amplitude.
(3) To modulate the noise in the experiment, I used an arbitrary wave generator to generate the initial white noise. Then, by feeding the bias control signal and noise signal together into the comparator LT1016, statistical modulation of the noise characteristics was achieved.
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| Current Status of Research Progress |
Current Status of Research Progress
2: Research has progressed on the whole more than it was originally planned.
Reason
Based on the current results, I have achieved the predetermined goal. This laid the foundation and good expectations for the next-year experiments. Moreover, some related research results on noise-assisted Ising machine with asymmetric nonlinearity were also presented at the domestic conference.
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| Strategy for Future Research Activity |
(1) Connect circuit modules (such as noise modulation circuit) with spin wave measurement systems (e.g., vector network analyzer). This can achieve the measurement and modulation of time-domain spin wave signals.
(2) Expand testing results from being limited to white noise to at least four types of colored noise conditions.
(3) Typically, achieving the highest success rate for different classes of problems (COPs) requires different spin coupling strengths and noise conditions. Therefore, in constructing hardware for spin wave GIMs, challenging COPs relevant to real-world scenarios are chosen as benchmarks. Initially, parameter ranges are roughly determined through simulations.Subsequently, optimal system parameters are determined through experiments.
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| Causes of Carryover |
After purchasing some research hardware, there is still a little remaining. I will mainly use it for expenses such as stationery and printing expenses during the next-year research.
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