The bandwidth limit between cryogenic and room-temperature environments is a critical bottleneck in superconducting noisy intermediate-scale quantum computers. This paper presents the first trial of algorithm-aware system-level optimization to solve this issue by targeting the quantum approximate optimization algorithm. Our counter-based cryogenic architecture using single-flux quantum logic shows exponential bandwidth reduction and decreases heat inflow and peripheral power consumption of inter-temperature cables, which contributes to the scalability of superconducting quantum computers.
{"title":"Inter-Temperature Bandwidth Reduction in Cryogenic QAOA Machines","authors":"Yosuke Ueno;Yuna Tomida;Teruo Tanimoto;Masamitsu Tanaka;Yutaka Tabuchi;Koji Inoue;Hiroshi Nakamura","doi":"10.1109/LCA.2023.3322700","DOIUrl":"10.1109/LCA.2023.3322700","url":null,"abstract":"The bandwidth limit between cryogenic and room-temperature environments is a critical bottleneck in superconducting noisy intermediate-scale quantum computers. This paper presents the first trial of algorithm-aware system-level optimization to solve this issue by targeting the quantum approximate optimization algorithm. Our counter-based cryogenic architecture using single-flux quantum logic shows exponential bandwidth reduction and decreases heat inflow and peripheral power consumption of inter-temperature cables, which contributes to the scalability of superconducting quantum computers.","PeriodicalId":51248,"journal":{"name":"IEEE Computer Architecture Letters","volume":"23 1","pages":"6-9"},"PeriodicalIF":2.3,"publicationDate":"2023-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136053842","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-09-29DOI: 10.1109/LCA.2023.3320670
Seunghak Lee;Ki-Dong Kang;Gyeongseo Park;Nam Sung Kim;Daehoon Kim
Row Hammer (RH) is a circuit-level phenomenon where repetitive activation of a DRAM row causes bit-flips in adjacent rows. Prior studies that rely on extra refreshes to mitigate RH vulnerability demonstrate that bit-flips can be prevented effectively. However, its implementation is challenging due to the significant performance degradation and energy overhead caused by the additional extra refresh for the RH mitigation. To overcome challenges, some studies propose techniques to mitigate the RH attack without relying on extra refresh. These techniques include delaying the activation of an aggressor row for a certain amount of time or swapping an aggressor row with another row to isolate it from victim rows. Although such techniques do not require extra refreshes to mitigate RH, the activation delaying technique may result in high-performance degradation in false-positive cases, and the swapping technique requires high storage overheads to track swap information. We propose NoHammer