-
近年来超导量子计算的研究方兴未艾, 随着谷歌宣布首次实现“量子优势”, 这一领域的研究受到了人们进一步的广泛关注. 超导量子比特是具有量子化能级、量子态叠加和量子态纠缠等典型量子特性的宏观器件, 通过电磁脉冲信号控制磁通量、电荷或具有非线性电感和无能量耗散的约瑟夫森结上的位相差, 可对量子态进行精确调控, 从而实现量子计算和量子信息处理. 超导量子比特有着诸多方面的优势, 很有希望成为普适量子计算的核心组成部分. 以铌或其他硬金属(如钽等)为首层大面积材料制备的超导量子比特及辅助器件(简称铌基器件)拥有其独特的优点以及进一步发展的空间, 目前已引起越来越多的兴趣. 本文将介绍常见的多种超导量子比特的基本构成和工作原理, 进而按照器件加工的一般顺序, 从基片选择和预处理、薄膜生长、图形转移、刻蚀和约瑟夫森结的制备等方面详细介绍铌基超导量子比特及其辅助器件的多种制备工艺, 为超导量子比特的制备提供一个可借鉴的清晰的工艺过程. 最后, 介绍若干制备铌基超导量子比特与辅助器件的具体例子, 并对器件制备的工艺与方法的优化做展望.Over the past two decades significant advances have been made in the research of superconducting quantum computing and quantum simulation, in particular of the device design and fabrication that leads to ever-increasing superconducting qubit coherence times and scales. With Google’s announcement of the realization of “quantum supremacy”, superconducting quantum computing has attracted even more attention. Superconducting qubits are macroscopic objects with quantum properties such as quantized energy levels and quantum-state superposition and entanglement. Their quantum states can be precisely manipulated by tuning the magnetic flux, charge, and phase difference of the Josephson junctions with nonlinear inductance through electromagnetic pulse signals, thereby implementing the quantum information processing. They have advantages in many aspects and are expected to become the central part of universal quantum computing. Superconducting qubits and auxiliary devices prepared with niobium or other hard metals like tantalum as bottom layers of large-area components have unique properties and potentials for further development. In this paper the research work in this area is briefly reviewed, starting from the design and working principle of a variety of superconducting qubits, to the detailed procedures of substrate selection and pretreatment, film growth, pattern transfer, etching, and Josephson junction fabrication, and finally the practical superconducting qubit and their auxiliary device fabrications with niobium base layers are also presented. We aim to provide a clear overview for the fabrication process of these superconducting devices as well as an outlook for further device improvement and optimization in order to help establish a perspective for future progress.
-
Keywords:
- superconducting qubit/
- device fabrication/
- quantum computing
[1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13] [14] [15] [16] [17] [18] [19] [20] [21] [22] [23] [24] [25] [26] [27] [28] [29] [30] [31] [32] [33] [34] [35] [36] [37] [38] [39] [40] [41] [42] [43] [44] [45] [46] [47] [48] [49] [50] [51] [52] [53] [54] [55] [56] [57] [58] [59] [60] [61] [62] [63] [64] [65] [66] [67] [68] [69] [70] [71] [72] [73] [74] [75] [76] [77] [78] [79] [80] [81] [82] [83] [84] [85] [86] [87] [88] [89] [90] [91] [92] [93] [94] [95] [96] [97] [98] [99] [100] [101] [102] [103] [104] [105] [106] [107] [108] [109] [110] [111] [112] [113] [114] [115] [116] [117] [118] [119] [120] [121] [122] [123] [124] [125] [126] [127] [128] [129] [130] [131] [132] [133] [134] [135] [136] [137] [138] [139] [140] [141] [142] [143] [144] [145] [146] [147] [148] [149] [150] [151] [152] [153] [154] [155] [156] -
Deposition Sputtered HiPIMS opt HiPIMS norm T1/μs 56 ± 12 33 ± 2 17 ± 9 RRR 8.9 ± 0.1 5.0 ± 0.2 2.9 ± 0.1 Tc/K 9.0 ± 0.1 8.6 ± 0.1 8.1 ± 0.1 GSA/nm2 1140 ± 70 500 ± 50 180 ± 30 Nb 61 ± 3 64 ± 3 45 ± 2 NbOx 15.1 ± 0.2 16.0 ± 0.3 20.4 ± 0.8 NbO 0 ± 2 0 ± 1 5 ± 1 NbO2 3.1 ± 0.4 3.5 ± 0.2 10 ± 2 Nb2O5 20 ± 1 15.9 ± 0.8 19 ± 2 Suboxide 19 ± 2 20 ± 1 36 ± 2 Processa In vacuo cleaning w/μm f0/GHz Qi-H×106 Qi-L×106 (A) Sputter 100 eV Ar+mill for 2 min 3
153.833
6.1294.30
4.500.16
0.40(B) E-beam 60 eV Ar+mill for 2 min 3
153.810
6.0899.90
4.400.66
0.72(C) MBE None 6
154.973
6.1205.70
4.330.53
0.76(D) MBE LLbanneal 3
153.773
6.1256.58
5.380.75
0.80(E) MBE LLband 850 ℃ anneal 3
153.876
6.12710.10
6.401.15
0.92 -
[1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13] [14] [15] [16] [17] [18] [19] [20] [21] [22] [23] [24] [25] [26] [27] [28] [29] [30] [31] [32] [33] [34] [35] [36] [37] [38] [39] [40] [41] [42] [43] [44] [45] [46] [47] [48] [49] [50] [51] [52] [53] [54] [55] [56] [57] [58] [59] [60] [61] [62] [63] [64] [65] [66] [67] [68] [69] [70] [71] [72] [73] [74] [75] [76] [77] [78] [79] [80] [81] [82] [83] [84] [85] [86] [87] [88] [89] [90] [91] [92] [93] [94] [95] [96] [97] [98] [99] [100] [101] [102] [103] [104] [105] [106] [107] [108] [109] [110] [111] [112] [113] [114] [115] [116] [117] [118] [119] [120] [121] [122] [123] [124] [125] [126] [127] [128] [129] [130] [131] [132] [133] [134] [135] [136] [137] [138] [139] [140] [141] [142] [143] [144] [145] [146] [147] [148] [149] [150] [151] [152] [153] [154] [155] [156]
计量
- 文章访问数:6184
- PDF下载量:277
- 被引次数:0