High efficiency NbN nanowire superconducting single photon detectors fabricated on MgO substrates from a low temperature process

Abstract

. (2008). High efficiency NbN nanowire superconducting single photon detectors fabricated on MgO substrates from a low temperature process. Optics Express, 16(5), 3191-3196. DOI: 10.1364/OE.16.003191 General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights.• Users may download and print one copy of any publication from the public portal for the purpose of private study or research.• You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal ? Take down policyIf you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim. Abstract:We demonstrate high-performance nanowire superconducting single photon detectors (SSPDs) on bN thin films grown at a temperature compatible with monolithic integration. NbN films ranging from 150nm to 3nm in thickness were deposited by dc magnetron sputtering on MgO substrates at 400 • C. SSPDs were fabricated on high quality NbN films of different thickness (7 to 3nm) deposited under optimal conditions. Electrical and optical characterizations were performed on the SSPDs. The highest QE value measured at 4.2K is 20% at 1300nm. Berggren, "Nanowire Single-photon detector with an integrated optical cavity and anti-reflection coating" Opt. Express 14(2), 527-534 (2006). 5. K. Iizuka, K. Matsumaru, T. Suzuki, H. Hirose, K. Suzuki, and H. Okamoto, "Arsenic-free GaAs substrate preparation and direct growth of GaAs/AlGaAs multiple quantum well without buffer layer" J. Cryst. Growth 150(1 -4 pt 1), 13-17 (1995 Gol'tsman, and A. Semenov, "Detection efficiency of large-active-area NbN single-photon superconducting detectors in the ultraviolet to near-infrared range" Appl.

Nanowire superconducting single-photon detectors on GaAs for integrated quantum photonic applications

“…We previously developed a low-temperature deposition process ͑T S = 400°C, quenched growth͒ on MgO, which yielded high quality NbN thin films. 8 However, films deposited on GaAs at T S = 400°C did not reach the same quality as the films on MgO. 11 We found that the reason of this degradation was that, at 400°C, As oxide ͑AsO and As 2 O 3 ͒ evaporated from the GaAs substrate during the baking ͑6-8 h͒ and the deposition procedure ͑30 min͒, which resulted in poor morphology of the substrate surface and thus of deposited films.…”

“…Superconducting singlephoton detectors ͑SSPDs͒, 5 based on the photon-induced creation of resistive regions ͑hot spots͒ in nanowires biased close to their critical current, have shown detection efficiencies of up to 30% at = 1.3 m, dark counts in the range of few hertz 5 and are extremely fast ͑with count rates approaching the gigahertz range͒. 6,7 SSPDs have so far been fabricated only on sapphire, 5 MgO, 8 and Si 9 substrates, which are not suitable for the integration with single photon sources. The fabrication of SSPDs on GaAs would enable integration with all the circuitry required for photonic quantum information processing, since GaAs readily lends itself to the largescale production of single-photon sources, 10 waveguides, interferometers, and phase modulators.…”

“…High substrate temperatures T S Ͼ 800°C are used on sapphire substrates, 5,8 to promote the surface diffusion of the sputtered particles, resulting in films with high crystalline quality. We previously developed a low-temperature deposition process ͑T S = 400°C, quenched growth͒ on MgO, which yielded high quality NbN thin films.…”

Ultrathin NbN Films for Superconducting Single-Photon Detectors

“…SSPDs are typically made by patterning a meander-type nanostructure in an ultrathin (≈ 5 nm) film deposited on a sapphire [1], MgO [7], or, recently, 3C-SiC/Si [8] single-crystal substrates. Single-crystal quality NbN films are deposited by either DC or RF reactive magnetron sputtering on substrates maintained at the 700-850…”

A carrier relaxation bottleneck probed in single InGaAs quantum dots using integrated superconducting single photon detectors

“…To directly observe such relaxation bottleneck effects, superconducting single photon detectors (SSPDs) are suitable due to their near unity quantum efficiency and picosecond timing resolution 10,11 . Building up on recent progress in this field 12-14 , we developed highly efficient 15,16 NbNSSPDs on GaAs 17 and demonstrated the monolithic integration of InGaAs QDs as single photon emitters together with waveguides and detectors on a single chip 18 . In this letter, we compare photoluminescence (PL) dynamics recorded from a single dot with confocal off-chip detectors with on-chip PL using integrated SSPDs that provide temporal resolution better than 70 ps.…”