Change search
Refine search result
1 - 18 of 18
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 1. Cheng, Y.
    et al.
    Chi, X.
    Gu, C.
    Zou, K.
    Zichi, Julien
    KTH, School of Engineering Sciences (SCI), Applied Physics, Quantum and Biophotonics.
    Chen, S.
    Liu, H.
    Zwiller, Val
    KTH, School of Engineering Sciences (SCI), Applied Physics, Quantum and Biophotonics.
    Hu, X.
    Experimental demonstration of superconducting nanowire single-photon detectors integrated with current reservoirs2018In: Optics InfoBase Conference Papers, OSA - The Optical Society , 2018Conference paper (Refereed)
    Abstract [en]

    We experimentally demonstrate the superconducting nanowire single-photon detectors integrated with current reservoirs that function as low-noise pre-amplifiers to increase the signal-to-noise ratio of detectors' outputs.

  • 2.
    Chi, Xiaoming
    et al.
    Tianjin Univ, Sch Precis Instrument & Optoelect Engn, Tianjin 300072, Peoples R China.;Minist Educ, Key Lab Optoelect Informat Sci & Technol, Tianjin 300072, Peoples R China..
    Zou, Kai
    Tianjin Univ, Sch Precis Instrument & Optoelect Engn, Tianjin 300072, Peoples R China.;Minist Educ, Key Lab Optoelect Informat Sci & Technol, Tianjin 300072, Peoples R China..
    Gu, Chao
    Tianjin Univ, Sch Precis Instrument & Optoelect Engn, Tianjin 300072, Peoples R China.;Minist Educ, Key Lab Optoelect Informat Sci & Technol, Tianjin 300072, Peoples R China..
    Zichi, Julien
    KTH, School of Engineering Sciences (SCI), Applied Physics, Quantum and Biophotonics.
    Cheng, Yuhao
    Tianjin Univ, Sch Precis Instrument & Optoelect Engn, Tianjin 300072, Peoples R China.;Minist Educ, Key Lab Optoelect Informat Sci & Technol, Tianjin 300072, Peoples R China..
    Hu, Nan
    Tianjin Univ, Sch Precis Instrument & Optoelect Engn, Tianjin 300072, Peoples R China.;Minist Educ, Key Lab Optoelect Informat Sci & Technol, Tianjin 300072, Peoples R China..
    Lan, Xiaojian
    Tianjin Univ, Sch Precis Instrument & Optoelect Engn, Tianjin 300072, Peoples R China.;Minist Educ, Key Lab Optoelect Informat Sci & Technol, Tianjin 300072, Peoples R China..
    Chen, Shufan
    Tianjin Univ, Sch Precis Instrument & Optoelect Engn, Tianjin 300072, Peoples R China.;Minist Educ, Key Lab Optoelect Informat Sci & Technol, Tianjin 300072, Peoples R China..
    Lin, Zuzeng
    KTH, School of Engineering Sciences (SCI), Applied Physics. Tianjin Univ, Sch Precis Instrument & Optoelect Engn, Tianjin 300072, Peoples R China.;Minist Educ, Key Lab Optoelect Informat Sci & Technol, Tianjin 300072, Peoples R China..
    Zwiller, Val
    KTH, School of Engineering Sciences (SCI), Applied Physics, Quantum and Biophotonics.
    Hu, Xiaolong
    Tianjin Univ, Sch Precis Instrument & Optoelect Engn, Tianjin 300072, Peoples R China.;Minist Educ, Key Lab Optoelect Informat Sci & Technol, Tianjin 300072, Peoples R China..
    Fractal superconducting nanowire single-photon detectors with reduced polarization sensitivity2018In: Optics Letters, ISSN 0146-9592, E-ISSN 1539-4794, Vol. 43, no 20, p. 5017-5020Article in journal (Refereed)
    Abstract [en]

    We demonstrate superconducting nanowire single-photon detectors (SNSPDs) based on a fractal design of the nanowires to reduce the polarization sensitivity of detection efficiency. We patterned niobium titanium nitride thin films into Peano curves with a linewidth of 100 nm and integrated the nanowires with optical microcavities to enhance their optical absorption. At a base temperature of 2.6 K, the fractal SNSPD exhibited a polarization-maximum device efficiency of 67% and a polarization-minimum device efficiency of 61% at a wavelength of 1550 nm. Therefore, the polarization sensitivity, defined as their ratio, was 1.1, lower than the polarization sensitivity of the SNSPDs in the meander design. The reduced polarization sensitivity of the detector could be maintained for higher-order spatial modes in multimode optical fibers and could tolerate misalignment between the optical mode and the detector. This fractal design is applicable to both amorphous and polycrystalline materials that are commonly used for making SNSPDs.

  • 3.
    Chi, Xiaoming
    et al.
    Tianjin Univ, Sch Precis Instrument & Optoelect Engn, Tianjin, Peoples R China.;Minist Educ, Key Lab Optoelect Informat Sci & Technol, Tianjin, Peoples R China..
    Zou, Kai
    Tianjin Univ, Sch Precis Instrument & Optoelect Engn, Tianjin, Peoples R China.;Minist Educ, Key Lab Optoelect Informat Sci & Technol, Tianjin, Peoples R China..
    Hu, Nan
    Tianjin Univ, Sch Precis Instrument & Optoelect Engn, Tianjin, Peoples R China.;Minist Educ, Key Lab Optoelect Informat Sci & Technol, Tianjin, Peoples R China..
    Zichi, Julien
    KTH, School of Engineering Sciences (SCI), Applied Physics.
    Zwiller, Val
    KTH, School of Engineering Sciences (SCI), Applied Physics.
    Hu, Xiaolong
    Tianjin Univ, Sch Precis Instrument & Optoelect Engn, Tianjin, Peoples R China.;Minist Educ, Key Lab Optoelect Informat Sci & Technol, Tianjin, Peoples R China..
    IEEE, GP
    RF-amplifier-free superconducting nanowire single-photon detector system2018In: 2018 ASIA COMMUNICATIONS AND PHOTONICS CONFERENCE (ACP), IEEE , 2018Conference paper (Refereed)
    Abstract [en]

    We used a superconducting nanowire single photon detector integrated th a current reservoir in a closed-cycle cryocooler to demonstrate

  • 4.
    Gourgues, Ronan
    et al.
    Single Quantum BV, NL-2628 CH Delft, Netherlands..
    Los, Johannes W. N.
    Single Quantum BV, NL-2628 CH Delft, Netherlands..
    Zichi, Julien
    KTH, School of Engineering Sciences (SCI), Applied Physics, Quantum and Biophotonics.
    Chang, Jin
    Delft Univ Technol, Fac Appl Sci, ImPhys Dept, Opt Res Grp, Lorentzweg 1, NL-2628 CJ Delft, Netherlands..
    Kalhor, Nima
    Single Quantum BV, NL-2628 CH Delft, Netherlands..
    Bulgarini, Gabriele
    Single Quantum BV, NL-2628 CH Delft, Netherlands..
    Borenbos, Sander N.
    Single Quantum BV, NL-2628 CH Delft, Netherlands..
    Zwiller, Val
    KTH, School of Engineering Sciences (SCI), Applied Physics, Quantum and Biophotonics.
    Zadeh, Iman Esmaeil
    Delft Univ Technol, Fac Appl Sci, ImPhys Dept, Opt Res Grp, Lorentzweg 1, NL-2628 CJ Delft, Netherlands..
    Superconducting nanowire single photon detectors operating at temperature from 4 to 7 K2019In: Optics Express, ISSN 1094-4087, E-ISSN 1094-4087, Vol. 27, no 17, p. 24601-24609Article in journal (Refereed)
    Abstract [en]

    We experimentally investigate the performance of NbTiN superconducting nanowire single photon detectors above the base temperature of a conventional Gifford-McMahon cryocooler (2.5 K). By tailoring design and thickness (8-13 nm) of the detectors, high performance, high operating temperature, single-photon detection from the visible to telecom wavelengths are demonstrated. At 4.3 K, a detection efficiency of 82 % at 785 nm wavelength and a timing jitter of 30 +/- 0.3 ps are achieved. In addition, for 1550 nm and similar operating temperature we measured a detection efficiency as high as 64 %. Finally, we show that at temperatures up to 7 K, unity internal efficiency is maintained for the visible spectrum. Our work is particularly important to allow for the large scale implementation of superconducting single photon detectors in combination with heat sources such as free-space optical windows, cryogenic electronics, microwave sources and active optical components for complex quantum optical experiments and bio-imaging.

  • 5.
    Gourgues, Ronan
    et al.
    Single Quantum BV, NL-2628 CH Delft, Netherlands..
    Zadeh, Iman Esmaeil
    Single Quantum BV, NL-2628 CH Delft, Netherlands.;Delft Univ Technol, ImPhys Dept, Opt Res Grp, Fac Appl Sci, Lorentzweg 1, NL-2628 CJ Delft, Netherlands..
    Elshaari, Ali W.
    KTH, School of Engineering Sciences (SCI), Applied Physics.
    Bulgarini, Gabriele
    Single Quantum BV, NL-2628 CH Delft, Netherlands..
    Los, Johannes W. N.
    Single Quantum BV, NL-2628 CH Delft, Netherlands..
    Zichi, Julien
    KTH, School of Engineering Sciences (SCI), Applied Physics, Quantum and Biophotonics.
    Dalacu, Dan
    Natl Res Council Canada, Ottawa, ON K1A 0R6, Canada..
    Poole, Philip J.
    Natl Res Council Canada, Ottawa, ON K1A 0R6, Canada..
    Dorenbos, Sander N.
    Single Quantum BV, NL-2628 CH Delft, Netherlands..
    Zwiller, Val
    KTH, School of Engineering Sciences (SCI), Applied Physics, Quantum and Biophotonics.
    Controlled integration of selected detectors and emitters in photonic integrated circuits2019In: Optics Express, ISSN 1094-4087, E-ISSN 1094-4087, Vol. 27, no 3, p. 3710-3716Article in journal (Refereed)
    Abstract [en]

    Integration of superconducting nanowire single-photon detectors and quantum sources with photonic waveguides is crucial for realizing advanced quantum integrated circuits. However, scalability is hindered by stringent requirements on high-performance detectors. Here we overcome the yield limitation by controlled coupling of photonic channels to pre-selected detectors based on measuring critical current, timing resolution, and detection efficiency. As a proof of concept of our approach, we demonstrate a hybrid on-chip full-transceiver consisting of a deterministically integrated detector coupled to a selected nanowire quantum dot through a filtering circuit made of a silicon nitride waveguide and a ring resonator filter, delivering 100 dB suppression of the excitation laser. In addition, we perform extensive testing of the detectors before and after integration in the photonic circuit and show that the high performance of the superconducting nanowire detectors, including timing jitter down to 23 +/- 3 ps, is maintained. Our approach is fully compatible with wafer-level automated testing in a cleanroom environment. 

  • 6.
    Gu, C.
    et al.
    China.
    Chi, X.
    China.
    Cheng, Y.
    China.
    Zichi, Julien
    KTH, School of Engineering Sciences (SCI), Applied Physics, Quantum and Biophotonics.
    Hu, N.
    China.
    Lan, X.
    Chona.
    Zou, K.
    China.
    Chen, S.
    China.
    Lin, Z.
    China.
    Zwiller, Val
    KTH, School of Engineering Sciences (SCI), Applied Physics, Quantum and Biophotonics.
    Hu, X.
    China.
    Fractal superconducting nanowire single-photon detectors with low polarization sensitivity2018In: Optics InfoBase Conference Papers, Optical Society of America, 2018Conference paper (Refereed)
    Abstract [en]

    We demonstrated a fractal superconducting nanowire single-photon detector and achieved 42% device efficiency and 1.04 polarization sensitivity. The low polarization sensitivity can be maintained for higher-order spatial modes in few-mode optical fibers.

  • 7. Hu, Xiaolong
    et al.
    Hu, Nan
    Meng, Yun
    Zou, Kai
    Xu, Liang
    Lan, Xiaojian
    Chi, Xiaoming
    Gu, Chao
    Cheng, Yuhao
    Wu, Hao
    Zichi, Julien
    KTH, School of Engineering Sciences (SCI), Applied Physics, Quantum and Biophotonics.
    Zwiller, Val
    KTH, School of Engineering Sciences (SCI), Applied Physics, Quantum and Biophotonics.
    Superconducting nanowire single-photon detectors at the infrared spectrum range: detection efficiency and timing jitter2019In: TERAHERTZ, RF, MILLIMETER, AND SUBMILLIMETER-WAVE TECHNOLOGY AND APPLICATIONS XII / [ed] Sadwick, LP Yang, T, 2019Conference paper (Refereed)
    Abstract [en]

    This paper reviews some recent research progress in superconducting nanowire single-photon detectors (SNSPDs) at the infrared spectrum range, with particular emphasis on detection efficiency and timing jitter. For detection efficiency, we present fractal SNSPDs with reduced polarization sensitivity; for timing jitter, we present two mechanisms of device timing jitter - vortex-crossing-induced timing jitter and spatial-inhomogeneity-induced timing jitter.

  • 8.
    Machhadani, Houssaine
    et al.
    Univ Grenoble Alpes, CEA INAC PHELIQS, 17 Av Martyrs, F-38000 Grenoble, France..
    Zichi, Julien
    KTH, School of Engineering Sciences (SCI), Applied Physics, Quantum and Biophotonics.
    Bougerol, Catherine
    Univ Grenoble Alpes, CNRS Inst Neel, 25 Av Martyrs, F-38000 Grenoble, France..
    Lequien, Stephane
    Univ Grenoble Alpes, CEA INAC MEM, 17 Av Martyrs, F-38000 Grenoble, France..
    Thomassin, Jean-Luc
    Univ Grenoble Alpes, CEA INAC PHELIQS, 17 Av Martyrs, F-38000 Grenoble, France..
    Mollard, Nicolas
    Univ Grenoble Alpes, CEA INAC MEM, 17 Av Martyrs, F-38000 Grenoble, France..
    Mukhtarova, Anna
    Univ Grenoble Alpes, CEA INAC PHELIQS, 17 Av Martyrs, F-38000 Grenoble, France..
    Zwiller, Val
    KTH, School of Engineering Sciences (SCI), Applied Physics.
    Gerard, Jean-Michel
    Univ Grenoble Alpes, CEA INAC PHELIQS, 17 Av Martyrs, F-38000 Grenoble, France..
    Monroy, Eva
    Univ Grenoble Alpes, CEA INAC PHELIQS, 17 Av Martyrs, F-38000 Grenoble, France..
    Improvement of the critical temperature of NbTiN films on III-nitride substrates2019In: Superconductors Science and Technology, ISSN 0953-2048, E-ISSN 1361-6668, Vol. 32, no 3, article id 035008Article in journal (Refereed)
    Abstract [en]

    In this paper, we study the impact of using III-nitride semiconductors (GaN, AlN) as substrates for ultrathin (11 nm) superconducting films of NbTiN deposited by reactive magnetron sputtering. The resulting NbTiN layers are (111)-oriented, fully relaxed, and they keep an epitaxial relation with the substrate. The higher critical superconducting temperature (T-c = 11.8 K) was obtained on AIN-on-sapphire, which was the substrate with smaller lattice mismatch with NbTiN. We attribute this improvement to a reduction of the NbTiN roughness, which appears associated with the relaxation of the lattice misfit with the substrate. On AlN-on-sapphire, superconducting nanowire single photon detectors were fabricated and tested, obtaining external quantum efficiencies that are in excellent agreement with theoretical calculations.

  • 9. Machhadani, Houssaine
    et al.
    Zichi, Julien
    KTH, School of Engineering Sciences (SCI), Applied Physics, Quantum and Biophotonics.
    Bougerol, Catherine
    Lequien, Stéphane
    Thomassin, Jean-Luc
    Mollard, Nicolas
    Mukhtarova, Anna
    Zwiller, Val
    KTH, School of Engineering Sciences (SCI), Applied Physics, Quantum and Biophotonics.
    Gérard, Jean-Michel
    Monroy, Eva
    Improvement of the critical temeprature of NbTiN films on III-nitride substrates2019In: Superconductors Science and Technology, ISSN 0953-2048, E-ISSN 1361-6668, Vol. 32, no 035008Article in journal (Refereed)
    Abstract [en]

    In this paper, we study the impact of using III-nitride semiconductors (GaN, AlN) as substrates for ultrathin (11 nm) superconducting films of NbTiN deposited by reactive magnetron sputtering. The resulting NbTiN layers are (111)-oriented, fully relaxed, and they keep an epitaxial relation with the substrate. The higher critical superconducting temperature (T c = 11.8 K) was obtained on AlN-on-sapphire, which was the substrate with smaller lattice mismatch with NbTiN. We attribute this improvement to a reduction of the NbTiN roughness, which appears associated with the relaxation of the lattice misfit with the substrate. On AlN-on-sapphire, superconducting nanowire single photon detectors were fabricated and tested, obtaining external quantum efficiencies that are in excellent agreement with theoretical calculations.

  • 10.
    Mukhtarova, Anna
    et al.
    Univ Grenoble Alpes, CEA, INAC, PHELIQS, 17 Av Martyrs, F-38000 Grenoble, France..
    Redaelli, Luca
    Univ Grenoble Alpes, CEA, INAC, PHELIQS, 17 Av Martyrs, F-38000 Grenoble, France..
    Hazra, Dibyendu
    Univ Grenoble Alpes, CEA, INAC, PHELIQS, 17 Av Martyrs, F-38000 Grenoble, France..
    Machhadani, Houssaine
    Univ Grenoble Alpes, CEA, INAC, PHELIQS, 17 Av Martyrs, F-38000 Grenoble, France..
    Lequien, Stephane
    Univ Grenoble Alpes, CEA, INAC, MEM, 17 Av Martyrs, F-38000 Grenoble, France..
    Hofheinz, Max
    Univ Grenoble Alpes, CEA, INAC, PHELIQS, 17 Av Martyrs, F-38000 Grenoble, France..
    Thomassin, Jean-Luc
    Univ Grenoble Alpes, CEA, INAC, PHELIQS, 17 Av Martyrs, F-38000 Grenoble, France..
    Gustavo, Frederic
    Univ Grenoble Alpes, CEA, INAC, PHELIQS, 17 Av Martyrs, F-38000 Grenoble, France..
    Zichi, Julien
    KTH, School of Engineering Sciences (SCI), Applied Physics, Quantum and Biophotonics.
    Zwiller, Val
    KTH, School of Engineering Sciences (SCI), Applied Physics, Quantum and Biophotonics. Univ Grenoble Alpes, CEA, INAC, PHELIQS, 17 Av Martyrs, F-38000 Grenoble, France.;Delft Univ Technol, Kavli Inst Nanosci, Lorentzweig 1, NL-2628 CJ Delft, Netherlands..
    Monroy, Eva
    Univ Grenoble Alpes, CEA, INAC, PHELIQS, 17 Av Martyrs, F-38000 Grenoble, France..
    Gerard, Jean-Michel
    Univ Grenoble Alpes, CEA, INAC, PHELIQS, 17 Av Martyrs, F-38000 Grenoble, France..
    Polarization-insensitive fiber-coupled superconducting-nanowire single photon detector using a high-index dielectric capping layer2018In: Optics Express, ISSN 1094-4087, E-ISSN 1094-4087, Vol. 26, no 13, p. 17697-17704Article in journal (Refereed)
    Abstract [en]

    Superconducting-nanowire single photon detectors (SNSPDs) are able to reach near-unity detection efficiency in the infrared spectral range. However, due to the intrinsic asymmetry of nanowires, SNSPDs are usually very sensitive to the polarization of the incident radiation, their responsivity being maximum for light polarized parallel to the nanowire length (transverse-electric (TE) polarization). Here, we report on the reduction of the polarization sensitivity obtained by capping NbN-based SNSPDs with a high-index SiNx dielectric layer, which reduces the permittivity mismatch between the NbN wire and the surrounding area. Experimentally, a polarization sensitivity below 0.1 is obtained both at 1.31 and 1.55 mu m, in excellent agreement with simulations.

  • 11. Mukhtarova, Anna
    et al.
    Redaelli, Luca
    Hazra, Dibyendu
    Machhadani, Houssaine
    Lequien, Stéphane
    Hofheinz, Max
    Thomassin, Jean-Luc
    Gustavo, Frederic
    Zichi, Julien
    Zwiller, Val
    KTH, School of Engineering Sciences (SCI), Applied Physics, Quantum and Biophotonics.
    Monroy, Eva
    Gérard, Jean-Michel
    Polarization-insensitive fiber-coupled superconducting-nanowire single photon detector using high-index dielectric capping layer2018In: Optics Express, ISSN 1094-4087, E-ISSN 1094-4087, Vol. 26, no 13Article in journal (Refereed)
    Abstract [en]

    Superconducting-nanowire single photon detectors (SNSPDs) are able to reach near-unity detection efficiency in the infrared spectral range. However, due to the intrinsic asymmetry of nanowires, SNSPDs are usually very sensitive to the polarization of the incident radiation, their responsivity being maximum for light polarized parallel to the nanowire length (transverse-electric (TE) polarization). Here, we report on the reduction of the polarization sensitivity obtained by capping NbN-based SNSPDs with a high-index SiNx dielectric layer, which reduces the permittivity mismatch between the NbN wire and the surrounding area. Experimentally, a polarization sensitivity below 0.1 is obtained both at 1.31 and 1.55 μm, in excellent agreement with simulations.

  • 12.
    Schweickert, Lucas
    et al.
    KTH, School of Engineering Sciences (SCI), Applied Physics, Quantum and Biophotonics.
    Jöns, Klaus D.
    KTH, School of Engineering Sciences (SCI), Applied Physics, Quantum and Biophotonics.
    Lettner, Thomas
    KTH, School of Engineering Sciences (SCI), Applied Physics, Quantum and Biophotonics.
    Zeuner, Katharina
    Zichi, Julien
    KTH, School of Engineering Sciences (SCI), Applied Physics, Quantum and Biophotonics.
    Elshaari, Ali W.
    KTH, School of Engineering Sciences (SCI), Applied Physics, Quantum and Biophotonics.
    Fognini, A.
    Zadeh, I. E.
    Zwiller, Val
    KTH, School of Engineering Sciences (SCI), Applied Physics, Quantum and Biophotonics.
    Generating, manipulating and detecting quantum states of light at the nanoscale2018In: Optics InfoBase Conference Papers, OSA - The Optical Society , 2018Conference paper (Refereed)
    Abstract [en]

    We generate, manipulate and detect light at the single photon level with semiconducting and superconducting nanowires.

  • 13.
    Wengerowsky, Soeren
    et al.
    Austrian Acad Sci, Inst Quantum Opt & Quantum Informat Vienna, A-1090 Vienna, Austria.;Vienna Ctr Quantum Sci & Technol, A-1090 Vienna, Austria..
    Joshi, Siddarth Koduru
    Austrian Acad Sci, Inst Quantum Opt & Quantum Informat Vienna, A-1090 Vienna, Austria.;Vienna Ctr Quantum Sci & Technol, A-1090 Vienna, Austria.;HH Wills Phys Lab, Quantum Engn Technol Labs, Bristol BS8 1FD, Avon, England.;Univ Bristol, Dept Elect & Elect Engn, Bristol BS8 1UB, Avon, England..
    Steinlechner, Fabian
    Austrian Acad Sci, Inst Quantum Opt & Quantum Informat Vienna, A-1090 Vienna, Austria.;Vienna Ctr Quantum Sci & Technol, A-1090 Vienna, Austria.;Fraunhofer Inst Appl Opt & Precis Engn IOF Jena, D-07745 Jena, Germany.;Friedrich Schiller Univ Jena, Abbe Ctr Photon, D-07745 Jena, Germany..
    Zichi, Julien
    KTH, School of Engineering Sciences (SCI), Applied Physics, Quantum and Biophotonics. Single Quantum BV, NL-2628 CJ Delft, Netherlands..
    Dobrovolskiy, Sergiy M.
    Single Quantum BV, NL-2628 CJ Delft, Netherlands..
    van der Molen, Rene
    Single Quantum BV, NL-2628 CJ Delft, Netherlands..
    Los, Johannes W. N.
    Single Quantum BV, NL-2628 CJ Delft, Netherlands..
    Zwiller, Val
    KTH, School of Engineering Sciences (SCI), Applied Physics, Quantum and Biophotonics. Single Quantum BV, NL-2628 CJ Delft, Netherlands..
    Versteegh, Marijn A. M.
    KTH, School of Engineering Sciences (SCI), Applied Physics, Quantum and Biophotonics.
    Mura, Alberto
    Ist Nazl Ric Metrol, I-10135 Turin, Italy..
    Calonico, Davide
    Ist Nazl Ric Metrol, I-10135 Turin, Italy..
    Inguscio, Massimo
    European Lab Nonlinear Spect LENS, I-50019 Sesto Fiorentino, Italy.;Univ Florence, Dept Phys & Astron, I-50019 Sesto Fiorentino, Italy.;CNR, I-00185 Rome, Italy..
    Huebel, Hannes
    Austrian Inst Technol, Ctr Digital Safety & Secur, A-1210 Vienna, Austria..
    Bo, Liu
    Austrian Acad Sci, Inst Quantum Opt & Quantum Informat Vienna, A-1090 Vienna, Austria.;Vienna Ctr Quantum Sci & Technol, A-1090 Vienna, Austria.;Natl Univ Def Technol, Coll Adv Interdisciplinary Studies, Changsha 410073, Hunan, Peoples R China..
    Scheidl, Thomas
    Austrian Acad Sci, Inst Quantum Opt & Quantum Informat Vienna, A-1090 Vienna, Austria.;Univ Vienna, Quantum Opt Quantum Nanophys & Quantum Informat, A-1090 Vienna, Austria..
    Zeilinger, Anton
    Austrian Acad Sci, Inst Quantum Opt & Quantum Informat Vienna, A-1090 Vienna, Austria.;Univ Vienna, Quantum Opt Quantum Nanophys & Quantum Informat, A-1090 Vienna, Austria..
    Xuereb, Andre
    Univ Malta, Dept Phys, MSD-2080 Msida, Malta..
    Ursin, Rupert
    Austrian Acad Sci, Inst Quantum Opt & Quantum Informat Vienna, A-1090 Vienna, Austria.;Vienna Ctr Quantum Sci & Technol, A-1090 Vienna, Austria..
    Entanglement distribution over a 96-km-long submarine optical fiber2019In: Proceedings of the National Academy of Sciences of the United States of America, ISSN 0027-8424, E-ISSN 1091-6490, Vol. 116, no 14, p. 6684-6688Article in journal (Refereed)
    Abstract [en]

    Quantum entanglement is one of the most extraordinary effects in quantum physics, with many applications in the emerging field of quantum information science. In particular, it provides the foundation for quantum key distribution (QKD), which promises a conceptual leap in information security. Entanglement-based QKD holds great promise for future applications owing to the possibility of device-independent security and the potential of establishing global-scale quantum repeater networks. While other approaches to QKD have already reached the level of maturity required for operation in absence of typical laboratory infrastructure, comparable field demonstrations of entanglement-based QKD have not been performed so far. Here, we report on the successful distribution of polarization-entangled photon pairs between Malta and Sicily over 96 km of submarine optical telecommunications fiber. We observe around 257 photon pairs per second, with a polarization visibility above 90%. Our results show that QKD based on polarization entanglement is now indeed viable in long-distance fiber links. This field demonstration marks the longest-distance distribution of entanglement in a deployed telecommunications network and demonstrates an international submarine quantum communication channel. This opens up myriad possibilities for future experiments and technological applications using existing infrastructure.

  • 14.
    Zichi, Julien
    KTH, School of Engineering Sciences (SCI), Applied Physics, Quantum and Biophotonics.
    NbTiN for improved superconducting detectors2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The physics of single photons is fascinating, by manipulating them we can observe and probe quantum effects. Doing so requires the fabrication and utilization of single photon sources, of which many types have been developed including quantum dots, trapped atoms and ions, and color centers. On the other end of the experiments, single photon detectors play a role of utmost importance, and while several types of detectors exist, superconducting nanowire single photon detectors are now the state-of-the-art technology. By offering near unity detection efficiency from the ultra-violet to the mid-infrared light spectrum, with negligible noise and excellent time resolution, they made possible many experiments that were previously technologically unfeasible. The same appealing characteristics have found a use in applications outside of the quantum optics framework, with notably light detection and ranging, biomedical imaging or CMOS circuits testing.In this thesis a controlled growth method for tailoring the characteristics of niobium titanium nitride in the framework of superconducting nanowire single photon detectors was developed. Reactive co-sputter deposition of niobium titanium nitride was shown to be a versatile method, both in terms of the degree of control over the material composition, and in the choice of substrates that it allows. Unity internal detection efficiency of detectors at telecom wavelengths was achieved by optimizing the niobium content in the material. The influence of lattice matching on the critical temperatures of films deposited at room temperature was investigated. The fabrication of superconducting nanowire single photon detectors on aluminum nitride-on-sapphire, on lithium niobate nano-waveguides, on gallium arsenide, and the integration on SiN waveguides was achieved. The material was used to fabricate detectors with optimized response for any linear polarization of the incoming photons by using a fractal architecture. Another method was proposed to achieve the same results by encapsulating meandering detectors in a high index dielectric material, resulting in a decrease of the permittivity mismatch between the nanowire material and its surrounding and therefore optimizing the efficiency for both orthogonal linear polarizations.Finally, detectors were fabricated from films developed in this work, and were operated to enable the implementation of polarization-based entanglement distribution in optical fibers in a real-conditions scenario, over a record distance of 96 km. This paves the way for the development of quantum communication networks using existing optical fiber links.

  • 15.
    Zichi, Julien
    et al.
    KTH, School of Engineering Sciences (SCI), Applied Physics, Quantum and Biophotonics.
    Chang, Chang
    Steinhauer, Stephan
    KTH, School of Engineering Sciences (SCI), Applied Physics, Quantum and Biophotonics.
    von Fieandt, Kristina
    Los, Johannes W. N.
    Visser, Gijs
    Kalhor, Nima
    Lettner, Thomas
    KTH, School of Engineering Sciences (SCI), Applied Physics, Quantum and Biophotonics.
    Elshaari, Ali W.
    KTH, School of Engineering Sciences (SCI), Applied Physics, Quantum and Biophotonics.
    Esmaeil Zadeh, Iman
    Zwiller, Val
    NbxTi1-xN low timing jitter single-photon detectors with unity internal detection efficiency at 1550 nmManuscript (preprint) (Other academic)
    Abstract [en]

    The requirements in quantum optics experiments for high single photon detectionefficiency, low timing jitter, low dark count rate and short dead time have been fulfilled withthe development of superconducting nanowire single photon detectors. Although they offer adetection efficiency above 90%, achieving a high time resolution in devices made ofamorphous materials is a challenge, particularly at temperatures above 0.8 K. Devices madefrom niobium nitride and niobium titanium nitride allow to reach the best timing jitter, but inturn have stronger requirements in terms of film quality to achieve a high efficiency. Here wetake advantage of the flexibility of reactive co-sputter deposition to tailor the composition ofNbxTi1-xN superconducting films, and show that a Nb fraction of x = 0.62 allows for thefabrication of detectors from films as thick as 9 nm and covering an active area of 20 μm,with a wide detection saturation plateau at telecom wavelengths and in particular at 1550 nm.This is a signature of an internal detection efficiency saturation, achieved while maintainingthe high time resolution associated with NbTiN and operation at 2.5K. With our optimizedrecipe, we reliably fabricated detectors with high critical current densities reaching asaturation plateau at 1550 nm with 80% system detection efficiency, and with a FWHMtiming jitter as low as 19.47 ps.

  • 16.
    Zichi, Julien
    et al.
    KTH, School of Engineering Sciences (SCI), Applied Physics, Quantum and Biophotonics.
    Chang, Jin
    Delft Univ Technol, Fac Appl Sci, ImPhys Dept, Opt Res Grp, Lorentzweg 1, NL-2628 CJ Delft, Netherlands..
    Steinhauer, Stephan
    KTH, School of Engineering Sciences (SCI), Applied Physics, Quantum and Biophotonics.
    Von Fieandt, Kristina
    Uppsala Univ, Angstrom Lab, Dept Chem, Inorgan Chem Res Programme, Box 538, SE-75121 Uppsala, Sweden..
    Los, Johannes W. N.
    Single Quantum BV, NL-2628 CH Delft, Netherlands..
    Visser, Gus
    Single Quantum BV, NL-2628 CH Delft, Netherlands..
    Kalhor, Nima
    Single Quantum BV, NL-2628 CH Delft, Netherlands..
    Lettner, Thomas
    KTH, School of Engineering Sciences (SCI), Applied Physics, Quantum and Biophotonics.
    Elshaari, Ali W.
    KTH, School of Engineering Sciences (SCI), Applied Physics, Quantum and Biophotonics.
    Zadeh, Iman Esmaeil
    Delft Univ Technol, Fac Appl Sci, ImPhys Dept, Opt Res Grp, Lorentzweg 1, NL-2628 CJ Delft, Netherlands..
    Zwiller, Val
    KTH, School of Engineering Sciences (SCI), Applied Physics, Quantum and Biophotonics. Single Quantum BV, NL-2628 CH Delft, Netherlands..
    Optimizing the stoichiometry of ultrathin NbTiN films for high-performance superconducting nanowire single-photon detectors2019In: Optics Express, ISSN 1094-4087, E-ISSN 1094-4087, Vol. 27, no 19, p. 26579-26587Article in journal (Refereed)
    Abstract [en]

    The requirements in quantum optics experiments for high single-photon detection efficiency. low timing jitter, low dark count rate and short dead time have been fulfilled with the development of superconducting nanowire single-photon detectors. Although they offer a detection efficiency above 90%, achieving a high time resolution in devices made of amorphous materials is a challenge, particularly at temperatures above 0.8 K. Devices made from niobium nitride and niobium titanium nitride allow us to reach the best timing jitter but. in turn, have stronger requirements in terms of film quality to achieve a high efficiency. Here we take advantage of the flexibility of reactive co-sputter deposition to tailor the composition of NbxTi1-xN superconducting films and show that a Nb fraction of x = 0.62 allows for the fabrication of detectors from films as thick as 9 nm and covering an active area of 20 mu m. with a wide detection saturation plateau at telecom wavelengths and in particular at 1550 nm. This is a signature of an internal detection efficiency saturation, achieved while maintaining the high time resolution associated with NbTiN and operation at 2.5K. With our optimized recipe, we reliably fabricated detectors with high critical current densities reaching a saturation plateau at 1550 nm with 80% system detection efficiency and with a FWHM timing jitter as low as 19.5 ps. Open Access Publishing Agreement

  • 17.
    Zichi, Julien
    et al.
    KTH, School of Engineering Sciences (SCI), Applied Physics, Quantum and Biophotonics.
    Gyger, Samuel
    KTH, School of Engineering Sciences (SCI), Applied Physics, Quantum and Biophotonics.
    Baghban, Mohammad Amin
    Elshaari, Ali W.
    KTH, School of Engineering Sciences (SCI), Applied Physics, Quantum and Biophotonics.
    Gallo, Katia
    Zwiller, Val
    KTH, School of Engineering Sciences (SCI), Applied Physics, Quantum and Biophotonics.
    An NbTiN superconducting single photon detector implemented on a LiNbO3 nano-waveguide at telecom wavelength2019In: Poster session T.Po2, 2019Conference paper (Refereed)
    Abstract [en]

    Fiber-coupled superconducting nanowire single photon detectors are a ubiquitous tool for quantum optics experiments as they offer near unity detection efficiency over a broad wavelength range, low dark count rate, excellent time resolution and high saturation rate. Nevertheless, advancing quantum optics experiments and applications beyond the few-photon limit requires large scale integrated systems of quantum sources and detectors. In recent years there has been a tremendous progress with integrating single photon detectors with a variety of photonic platforms. This includes attempts on ion-diffused waveguides in LiNbO3, a non-linear and electro-optic material with widespread use for signal processing, frequency conversion, and quantum optics devices. However the realization of superconducting detectors on single mode waveguides remains elusive. Here we present an NbTiN superconducting single photon detector integrated directly on a LiNbO3 single mode nanophotonic waveguide at telecom wavelength, with a high critical current density and a dark count rate of 3 mHz at 99% of its critical current.

  • 18.
    Zichi, Julien
    et al.
    KTH, School of Engineering Sciences (SCI), Applied Physics, Quantum and Biophotonics.
    Yang, Lily
    Gyger, Samuel
    KTH, School of Engineering Sciences (SCI), Applied Physics, Quantum and Biophotonics.
    Lettner, Thomas
    KTH, School of Engineering Sciences (SCI), Applied Physics, Quantum and Biophotonics.
    Errando-Herranz, Carlos
    KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
    Jöns, Klaus D.
    KTH, School of Engineering Sciences (SCI), Applied Physics, Quantum and Biophotonics.
    Baghban, Mohammad Amin
    Gallo, Katia
    Steinhauer, Stephan
    KTH, School of Engineering Sciences (SCI), Applied Physics, Quantum and Biophotonics.
    Zwiller, Val
    KTH, School of Engineering Sciences (SCI), Applied Physics, Quantum and Biophotonics.
    Heterogeneous integration of NbTiN by universal room temperature depositionManuscript (preprint) (Other academic)
    Abstract [en]

    Being the Nb-based compound with the highest known critical temperature, NbTiN is of particular interest for many applications. It is used in Josephson junctions for single flux quantum logic gates, as a superconducting electrode to contact semiconductor devices, and one important use is in superconducting nanowire single photon detectors. These detectors are the ideal candidate for on-chip integration in photonic circuits, offering near-unity detection efficiency, low noise and excellent time resolution, therefore it is desirable to implement them on a wide variety of platforms. However, it remains a challenge to deposit the superconducting material with a process suitable for heterogeneous integration, as the most widespread material, NbN, is associated with a deposition at a high temperature. Taking advantage of the possibility to deposit superconducting NbTiN with various stoichiometries by co-sputter deposition at room temperature, we demonstrate growth on six different substrates – silicon dioxide, silicon nitride, gallium arsenide, lithium niobate, [Pb(Mg1/3Nb2/3)O3]-x[PbTiO3] or PMN-PT, and aluminum nitride – in the same deposition run, and show that all the films exhibit superconducting properties with similar critical temperatures. We fabricated waveguide-compatible superconducting nanowire single photon detectors on five substrates, report short dead times for all devices with a narrow spread of performances, and discuss their different photon detection saturation behavior. Our method simplifies the fabrication of superconducting devices on a wide range of materials.

1 - 18 of 18
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf