2013 IEEE 14th International Superconductive Electronics Conference (ISEC)最新文献_第5页

Fabrication of NbN/Al-AlNx/NbN tunnel junctions on several kinds of substrates 几种衬底上NbN/Al-AlNx/NbN隧道结的制备

2013 IEEE 14th International Superconductive Electronics Conference (ISEC) Pub Date : 2013-07-07 DOI: 10.1109/ISEC.2013.6604313

H. Akaike, T. Funai, Shunya Sakamoto, A. Fujimaki

{"title":"Fabrication of NbN/Al-AlNx/NbN tunnel junctions on several kinds of substrates","authors":"H. Akaike, T. Funai, Shunya Sakamoto, A. Fujimaki","doi":"10.1109/ISEC.2013.6604313","DOIUrl":"https://doi.org/10.1109/ISEC.2013.6604313","url":null,"abstract":"We have evaluated the electrical characteristics of NbN/Al-AlNx/NbN tunnel junctions fabricated on sapphire-C or fused-silica substrates. NbN/Al-AlNx/NbN multilayers were prepared by reactive dc-magnetron sputtering deposition of lower and upper NbN layers, and rf-magnetron sputtering deposition of the Al layer, followed by radical-nitridation. The junctions showed low sub-gap leakage currents in the current-voltage characteristics at 4.2 K. The quality parameter, Rsg/Rn, where respective Rsg and Rn are the sub-gap resistance at 2 mV and junction resistance at 5 mV, was above 15. The gap voltage (Vg) was around 3.3 mV, which was reduced in comparison with Vg values of ~4.3 mV for junctions on MgO substrates. The reduced Vg was caused by superconducting properties of lower NbN layers deposited on the sapphire or fused-silica substrates. Uniformity in critical current (Ic) was relatively good, and the maximum-to-minimum spread in Ic was ±1.7% for 200 junctions on a sapphire substrate and ±2.0% for the junctions on a fused-silica substrate.","PeriodicalId":233581,"journal":{"name":"2013 IEEE 14th International Superconductive Electronics Conference (ISEC)","volume":"51 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121298861","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 4

Characterization of optical absorptance in superconducting nanowire single-photon detectors 超导纳米线单光子探测器的光吸收特性

2013 IEEE 14th International Superconductive Electronics Conference (ISEC) Pub Date : 2013-07-07 DOI: 10.1109/ISEC.2013.6604294

T. Yamashita, S. Miki, H. Terai, Zhen Wang

引用次数: 0

SFQ digital signal processing circuits for multi-quantum beam detectors using STJ array with neutron absorbers 带中子吸收器的STJ阵列多量子束探测器SFQ数字信号处理电路

2013 IEEE 14th International Superconductive Electronics Conference (ISEC) Pub Date : 2013-07-07 DOI: 10.1109/ISEC.2013.6604290

H. Myoren, Y. Akamatsu, R. Sasaki, Shoji Sato, M. Naruse, T. Taino

{"title":"SFQ digital signal processing circuits for multi-quantum beam detectors using STJ array with neutron absorbers","authors":"H. Myoren, Y. Akamatsu, R. Sasaki, Shoji Sato, M. Naruse, T. Taino","doi":"10.1109/ISEC.2013.6604290","DOIUrl":"https://doi.org/10.1109/ISEC.2013.6604290","url":null,"abstract":"We studied multi-quantum beam detectors using a superconducting tunnel junction (STJ) array with neutron absorbers. Using a neutron absorber for each of the STJs, we expected the STJ detector to exhibit a high spatial resolution and high detection efficiency for neutrons as well as radiative beams such as X-rays. To obtain diffraction patterns of the X-ray and neutrons, we propose the use of a multi-quantum beam detector using an STJ array and single flux quantum (SFQ) signal processing at low temperature because of its high-speed and low-power operation. The kinetic energy is determined for individual neutrons using time-of-flight-methods that employ SFQ time-to-digital converters (TDCs). To separately detect α-particles and γ-ray particles that are produced by the nuclear reaction between neutrons and boron, and X-ray photons, excess quasi-particle currents of the STJ detectors are processed by V/F type analog-to-digital converters and T-FF binary counters using SFQ digital circuits. To obtain the multiplexed readout of an STJ detector array, we designed a current bias switching circuit controlled by an SFQ driver for time-domain multiplexing. We designed the main circuits for this SFQ signal processing system and fabricated them using the ISTEC SRL Nb standard process II (STP2).","PeriodicalId":233581,"journal":{"name":"2013 IEEE 14th International Superconductive Electronics Conference (ISEC)","volume":"102 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126829563","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Evolution of internal energy distribution and terahertz radiation of a Josephson junctions stack 约瑟夫森结堆内部能量分布和太赫兹辐射的演化

2013 IEEE 14th International Superconductive Electronics Conference (ISEC) Pub Date : 2013-07-07 DOI: 10.1109/ISEC.2013.6604265

J. Yuan, Jun Li, A. Ishii, T. Hatano, Hua-bing Wang, Meng-Yue Li, D. An, Ya Huang, M. Ji, Xianjing Zhou, Peiheng Wu, S. Guénon, B. Gross, D. Koelle, R. Kleiner

{"title":"Evolution of internal energy distribution and terahertz radiation of a Josephson junctions stack","authors":"J. Yuan, Jun Li, A. Ishii, T. Hatano, Hua-bing Wang, Meng-Yue Li, D. An, Ya Huang, M. Ji, Xianjing Zhou, Peiheng Wu, S. Guénon, B. Gross, D. Koelle, R. Kleiner","doi":"10.1109/ISEC.2013.6604265","DOIUrl":"https://doi.org/10.1109/ISEC.2013.6604265","url":null,"abstract":"Being frequency tunable sources, Josephson junctions are attractive for the generation of high frequency electromagnetic radiation. Recently, coherent off-chip THz radiation with an extrapolated output power of some μW was observed. Different mechanisms, like geometry resonance and heating effect, have been raised to explain how the junctions in the stack are synchronized, while there is no consensus which has been reached. To get further understanding on this issue, it is expected to demonstrate the process that the electromagnetic field and thermal distribution evolve as the detected terahertz(THz) emission signal varies in experiment. To realize this goal, we developed a home-made system, by combining a low-temperature scanning laser microscope (LTSLM) and a THz interferometer. With this setup, we are able to simultaneously detect THz emission and observe LTSLM images. In this talk, we will report the unambiguous observation of the correlation between the standing wave patterns, the hotspot formation and the THz radiation characteristics of the Bi2Sr2CaCu2O8 (BSCCO) junctions stack with a mesa structure. We stress that this joint measurement setup will play an important role in studying solid state microwave or terahertz devices.","PeriodicalId":233581,"journal":{"name":"2013 IEEE 14th International Superconductive Electronics Conference (ISEC)","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130741520","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Performances of NbTiN superconducting nanowire single photon detector NbTiN超导纳米线单光子探测器的性能

2013 IEEE 14th International Superconductive Electronics Conference (ISEC) Pub Date : 2013-07-07 DOI: 10.1109/ISEC.2013.6604289

S. Miki, T. Yamashita, H. Terai, Zhen Wang

引用次数: 0

Influence of external magnetic fields on the inductive properties of rapid single-flux-quantum digital circuits 外磁场对快速单通量量子数字电路电感特性的影响

2013 IEEE 14th International Superconductive Electronics Conference (ISEC) Pub Date : 2013-07-07 DOI: 10.1109/ISEC.2013.6604269

R. Collot, P. Febvre, C. Fourie, J. Issler, Thierry Robert, J. Kunert, R. Stolz, H. Meyer

引用次数: 1

Low noise SQUID readout for detection of small magnetic field signal 低噪声SQUID读出检测小磁场信号

2013 IEEE 14th International Superconductive Electronics Conference (ISEC) Pub Date : 2013-07-07 DOI: 10.1109/ISEC.2013.6604292

Yongliang Wang, Xiaofeng Xu, Guofeng Zhang, Yang Qiu, Shulin Zhang, Xianyang Kong, Huiwu Wang, Yi Zhang, Xiaoming Xie

引用次数: 0

Measurement of quantum superposition states of a single spin with a superconducting resonator 用超导谐振器测量单自旋的量子叠加态

2013 IEEE 14th International Superconductive Electronics Conference (ISEC) Pub Date : 2013-07-07 DOI: 10.1109/ISEC.2013.6604286

M. Kawamura

引用次数: 0

High-frequency characteristics of dc-SQUIDs with magnetic nanoparticle patterns 具有磁性纳米粒子图案的直流鱿鱼的高频特性

2013 IEEE 14th International Superconductive Electronics Conference (ISEC) Pub Date : 2013-07-07 DOI: 10.1109/ISEC.2013.6604299

Hiroshi Ito, Soya Taniguchi, T. Okumura, H. Akaike, A. Fujimaki

{"title":"High-frequency characteristics of dc-SQUIDs with magnetic nanoparticle patterns","authors":"Hiroshi Ito, Soya Taniguchi, T. Okumura, H. Akaike, A. Fujimaki","doi":"10.1109/ISEC.2013.6604299","DOIUrl":"https://doi.org/10.1109/ISEC.2013.6604299","url":null,"abstract":"We studied high-frequency characteristics of dc-SQUIDs with magnetic-nanoparticle-film patterns, which would be applied to superconductor integrated circuits for reducing widths in passive transmission lines and for increasing coupling factors in transformers. The patterns were constructed by Fe3O4 nanoparticles (NPs) with an average diameter of 5 nm. The high-frequency characteristics were obtained by comparison in the resonant characteristics and threshold characteristics of the SQUIDs before and after formation of the patterns. The n-th resonant frequency (fn) was calculated from the n-th resonant voltage step of the SQUID, giving the LC product at fn. Here, L is the SQUID loop inductance, and C is the equivalent capacitance consisting of Josephson junction of the SQUID and the NP pattern. In SQUIDs with large NP patterns, the LC product increased from 8% to 260% at frequencies of 47 GHz or higher with the thickness of the pattern although the increase in inductance of the SQUID in threshold characteristics was from 0.9% to 5.5%. On the other hand, the increase in LC product caused by a small pattern was negligible regardless of a 7.6% increase in inductance in threshold characteristics.","PeriodicalId":233581,"journal":{"name":"2013 IEEE 14th International Superconductive Electronics Conference (ISEC)","volume":"78 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131136865","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Noise reduction in RSFQ logic gates for increasing operating speed and widening margins 降低RSFQ逻辑门的噪声，以提高操作速度和扩大余量

2013 IEEE 14th International Superconductive Electronics Conference (ISEC) Pub Date : 2013-07-07 DOI: 10.1109/ISEC.2013.6604273

Y. Kita, Hiromi Matsuoka, S. Miyajima, Masamitsu Tanaka, A. Fujimaki

引用次数: 0