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Elsinga, G.E. (author), Ishihara, Takashi (author), Hunt, J.C.R. (author)Direct numerical simulations up to Reλ = 1445 show that the scaling exponents for the enstrophy and the dissipation rate extrema are different and depend on the Reynolds number. A similar Reynolds number dependence of the scaling exponents is observed for the moments of the dissipation rate, but not for the moments of the enstrophy. Significant...journal article 2023
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Ishihara, R. (author), Hermias, J. (author), Neji, S. (author), Yu, K.Y. (author), van der Maas, M.C. (author), Nur, S. (author), Iwai, T. (author), Miyatake, T. (author), Miyahara, S. (author)Quantum computer chip based on spin qubits in diamond uses modules that are entangled with on-chip optical links. This enables an increased connectivity and a negligible crosstalk and error-rate when the number of qubits increases onchip. Here, 3D integration is the key enabling technology for a large-scale integration of the diamond spin...conference paper 2023
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Iwai, Toshiki (author), Kawaguchi, Kenichi (author), Miyatake, Tetsuya (author), Ishiguro, Tetsuro (author), Miyahara, Shoichi (author), Doi, Yoshiyasu (author), Nur, S. (author), Ishihara, R. (author), Sato, Shintaro (author)For quantum computing modules using diamond color centers, we propose an integrated structure of a quantum chip with photonic circuits and an interposer with electric circuits. The chip and interposer are connected via gold stud bumps using flip-chip bonding technology. For evaluating the proposed integrated structure, we bonded a test chip...conference paper 2023
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Miyatake, Tetsuya (author), Kawaguchi, Kenichi (author), Ohtomo, Manabu (author), Iwai, Toshiki (author), Ishiguro, Tetsuro (author), Doi, Yoshiyasu (author), Hermias, J. (author), Nur, S. (author), Ishihara, R. (author), Sato, Shintaro (author)Surface-activated direct bonding of diamond (100) and c-plane sapphire substrates is investigated using Ar atom beam irradiation and high-pressure contact at RT. The success probability of bonding strongly depends on the surface properties, i.e, atomic smoothness for the micron-order area and global flatness for the entire substrate....journal article 2023
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Elsinga, G.E. (author), Ishihara, T. (author), Hunt, J. C.R. (author)The Richardson-scaling law states that the mean square separation of a fluid particle pair grows according to twithin the inertial range and at intermediate times. The theories predicting this scaling regime assume that the pair separation is within the inertial range and that the dispersion is local, which means that only eddies at the scale...journal article 2022
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Li, Ye (author), Mirza Gheytaghi, Amir (author), Trifunovic, M. (author), Xu, Yuanxing (author), Zhang, Kouchi (author), Ishihara, R. (author)3D integration has well-developed for traditional CMOS technology operating at room temperature, but few studies have been performed for cryogenic applications such as quantum computers. In this paper, a wafer-to-wafer bonding of superconductive joints based on niobium nitride (NbN) is performed to demonstrate the possibility of 3D...journal article 2021
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XU, Y. (author), Unseld, F.K. (author), Corna, A. (author), Zwerver, A.M.J. (author), Sammak, A. (author), Brousse, D. (author), Samkharadze, Nodar (author), Amitonov, S. (author), Veldhorst, M. (author), Scappucci, G. (author), Ishihara, R. (author), Vandersypen, L.M.K. (author)Solid-state qubits integrated on semiconductor substrates currently require at least one wire from every qubit to the control electronics, leading to a so-called wiring bottleneck for scaling. Demultiplexing via on-chip circuitry offers an effective strategy to overcome this bottleneck. In the case of gate-defined quantum dot arrays, specific...journal article 2020
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Esteban, Miguel (author), Portugal-Pereira, Joana (author), Mclellan, Benjamin C. (author), Bricker, J.D. (author), Farzaneh, Hooman (author), Djalilova, Nigora (author), Ishihara, Keiichi N. (author), Takagi, Hiroshi (author), Roeber, Volker (author)In the aftermath of the Paris Agreements, many countries around the globe have pledged to reduce the amount of greenhouse gas emissions being released into the atmosphere. To do so, it is important that the amount of renewable energy in the electricity grid increases. However, there are worries of the capacity of the grid to cope with...journal article 2018
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- Xue, X. (author), Corna, A. (author), Samkharadze, Nodar (author), Veldhorst, M. (author), Ishihara, R. (author), Vandersypen, L.M.K. (author) abstract 2018
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Alfaro, J.A. (author), Sberna, P.M. (author), Silvestri, C. (author), Mastrangeli, Massimo (author), Ishihara, R. (author), Sarro, Pasqualina M (author)A novel, simple, low-cost method for the void-free filling of high aspect ratio (HAR) through-silicon-vias (TSVs) is presented. For the first-time pure indium, a type-I superconductor metal, is used to fill HAR vias, 300 to 500 μm in depth and 50 to 100 μm in diameter. The low electrical resistivity achieved without sintering, its...conference paper 2018
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Trifunovic, M. (author), Sberna, P.M. (author), Shimoda, T (author), Ishihara, R. (author)Printing of electronics has been gaining a lot of attention over the past decade as a low cost alternative to conventional electronic fabrication methods. A significant development in this area was the possibility to print a silicon precursor, polydihydrosilane, which can directly be transformed into polycrystalline silicon by an excimer laser...journal article 2017
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Vandersypen, L.M.K. (author), Bluhm, H (author), Clarke, J. S. (author), Dzurak, A. S. (author), Ishihara, R. (author), Morello, A. (author), Reilly, D. J. (author), Schreiber, L. R. (author), Veldhorst, M. (author)Semiconductor spins are one of the few qubit realizations that remain a serious candidate for the implementation of large-scale quantum circuits. Excellent scalability is often argued for spin qubits defined by lithography and controlled via electrical signals, based on the success of conventional semiconductor integrated circuits. However, the...journal article 2017
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Sberna, P.M. (author), Trifunovic, M. (author), Ishihara, R. (author)Currently, research has been focusing on printing and laser crystallization of cyclosilanes, bringing to life polycrystalline silicon (poly-Si) thin-film transistors (TFTs) with outstanding properties. However, the synthesis of these Sibased inks is generally complex and expensive. Here, we prove that a polysilane ink, obtained as a byproduct of...journal article 2017
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Elsinga, G.E. (author), Ishihara, T. (author), Goudar Vishwanathappa, M. (author), da Silva, C.B. (author), Hunt, J.C.R. (author)The scaling of turbulent motions is investigated by considering the flow in the eigenframe of the local strain-rate tensor. The flow patterns in this frame of reference are evaluated using existing direct numerical simulations of homogeneous isotropic turbulence over a Reynolds number range from up to 1131, and also with reference to data for...journal article 2017
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Trifunovic, M. (author), Shimoda, T (author), Ishihara, R. (author), Sberna, P.M. (author)Printing of electronics is pursued as a low-cost alternative to conventional manufacturing processes. In addition, owing to relatively low process temperatures, flexible substrates can be used enabling novel applications. Among flexible substrates, paper was found to be a particularly interesting candidate, since it has an order of magnitude...journal article 2017
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Sun, P. (author), Ishihara, R. (author), Charbon, E. (author)We proposed the world’s first flexible ultrathin-body single-photon avalanche diode (SPAD) as photon counting device providing a suitable solution to advanced implantable bio-compatible chronic medical monitoring, diagnostics and other applications. In this paper, we investigate the Geiger-mode performance of this flexible ultrathin-body SPAD...journal article 2016
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Ishihara, R. (author), Trifunovic, M. (author), Van der Zwan, M. (author)A method for low-temperature formation of a silicon/silicon-oxide structure on a substrate is described wherein the method comprises: forming a first (poly)silane layer over at least part of a substrate; transforming said first (poly)silane layer directly into a (crystalline) silicon layer by exposing said first (poly)silane layer to UV...patent 2016
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Vollebregt, S. (author), Ishihara, R. (author)Carbon nanotubes (CNT) have been proposed for many applications in integrated circuits (IC): ranging from transistors and interconnects to sensors and actuators. For these applications it is crucial to integrate CNT directly alongside electronics, something which has not been achieved before. In this work we demonstrate the direct growth of CNT...journal article 2016
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Sun, P. (author), Charbon, E. (author), Ishihara, R. (author)The first single-photon avalanche diode (SPAD) image sensor fully integrated on flexible substrate is reported. The design consists of an array of 1024 quenched pixels with CMOS readout and addressing circuitries. The flexible substrate was made compatible with sol-gel polymer, which will be used to imprint microlenses by quartz mold to improve...conference paper 2015
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Honjo, Y. (author), Moro, H. (author), Ishihara, M. (author), Otake, Y. (author)The ministry of land, infrastructures, transportation and tourism (MLIT) of the Japanese government maintains governmental managed river levee for the safety against flood whose total length is more than 10,000 km. The design standard of river levee had been traditionally done based on so called shape based specification, where levee is judged...conference paper 2015