Cryogenic-DRAM based memory system for scalable quantum computers: a feasibility study
Cryogenic-DRAM based memory system for scalable quantum computers: a feasibility study
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用于可扩展量子计算机的基于低温 DRAM 的存储系统：可行性研究
DOI：
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发表时间：
2017
期刊：
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通讯作者：
Moinuddin K. Qureshi
中科院分区：
文献类型：
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作者：
Swamit S. Tannu;Douglas M. Carmean;Moinuddin K. Qureshi
量子计算机可以通过利用量子比特（qubit）的特性来解决根本性的难题。它由一个量子衬底，连接到一个传统的计算机，称为控制处理器。控制处理器可以操纵和测量量子位的状态，并充当量子位和编程器之间的接口。不幸的是，量子比特对噪声非常敏感，为了最小化噪声，量子比特在低温下运行。为了构建可扩展的量子计算机，可以在低温下工作的控制处理器是必不可少的[3，14]。在本文中，我们专注于建立一个存储系统的低温控制处理器的挑战。可扩展的量子计算机将需要大容量的内存来存储量子纠错生成的程序和数据。为此，我们评估的可行性，低温DRAM为基础的存储器系统的特点，在低温下的商业DRAM模块。在本文中，我们报告的最低工作温度为55 DIRECT（共750 DRAM芯片组成），并分析了在低温下操作的商品DRAM设备的错误模式。我们的研究表明，很大一部分DRAM芯片可以在低至80K的温度下继续工作。这项研究是评估低温DRAM作为量子计算机主存储器的有效性的第一步。
A quantum computer can solve fundamentally difficult problems by utilizing properties of quantum bits (qubits). It consists of a quantum substrate, connected to a conventional computer, termed as control processor. A control processor can manipulate and measure the state of the qubits and act as an interface between qubits and the programmer. Unfortunately, qubits are extremely noise-sensitive, and to minimize the noise; qubits are operated at cryogenic temperatures. To build a scalable quantum computer, a control processor which can work at cryogenic temperatures is essential [3, 14]. In this paper, we focus on the challenges of building a memory system for a cryogenic control processor. A scalable quantum computer will require large memory capacity for storing the program and the data generated by the quantum error correction. To this end, we evaluate the feasibility of cryogenic DRAM-based memory system by characterizing commercial DRAM modules at cryogenic temperatures. In this paper, we report the minimum operational temperature for 55 DIMMs (consisting of a total of 750 DRAM chips) and analyze the error patterns in commodity DRAM devices operated at cryogenic temperatures. Our study shows that a significant fraction of DRAM chips continue to work at temperatures as low as 80K. This study is an initial step towards evaluating the effectiveness of cryogenic DRAM as a main memory for quantum computers.