Laboratory for Quantum Detectors

Scientific results:

• The influence of the implantation of tin ions on the properties of amorphous Ge₂Sb₂Te₅ thin films.

• Using noise thermometry we have determined that thermal relaxation in thin NbN films at temperatures higher than the critical temperature of superconductivity is limited mainly by thermal boundary resistance and can be modified by  structural disorder on the surface of the substrate. Moreover, for NbN films applied to a sapphire substrate it can be  observed that thermal relaxation occurs in the diffusive phonon regime, when the phonon mean  free path is shorter than the thickness of the film. The conclusions can be used for low-temperature devices based on NbN.

• Results of a quantum detector tomography research of micron-length SNSPD have been presented. The high internal efficiency of SNSPD detection allowed to extrude single- and double-proton efficiency from the count rate vs radiation power dependence and extract hot-spot interaction length. Experimental results  confirmed that regardless of the material or the resistance of the film, the hot-spot interaction length coincides with the width of the strip, which is a promising  feature for the creatjon of  a two-photon counter with high fidelity.

• Optical integrated circuits on a silicon nitride platform have been developed that are integrated with microfluidic channels for the research of liquids and gases.

• Tunneling contacts to individual semiconducting carbon  through a thin aluminum oxide film nanotubes have been designed and produced.

• An extensive set of data on superconductor single-photon detectors based on niobium nitride (NbN) has been accumulated that will allow to determine empirical correlations between performance and the normal-state resistance per square. The data has been reviewed in the context of a model in which the energy of photons triggers the movement of vortices.

• We have obtained results of a study of detection efficiency saturation in the wave length range of 400–1550 nm for superconductor single-photon NbN detectors with a width of the strip of up to 3 µm. The expected reduction of the plateau of detection efficiency saturation can be observed with an increase of the wavelength of the photon  and a decrease of the resistance of film layer.

• The photon count rate (PCR) of superconducting single-photon detectors made of Mo_xSi_1−x films shaped as a 2-μm-wide strip and a 115-nm-wide meander strip line has been studied experimentally as a function of the dc biasing current at different values of the perpendicular magnetic field. We argue that in the wide strip the absorbed photon destroys superconductivity locally via the vortex-antivortex mechanism for the emergence of resistance, while in the narrow meander superconductivity is destroyed across the whole strip line.

• The transport properties of two types of quasi-one-dimensional superconducting  microstructures  at ultra-low temperatures have been researched: narrow channels, densely packed in the form of a meander and chains of tunneling contacts «superconductor-insulator-superconductor». Both types of microstructures have demonstrated high values of high-frequency impedance and dynamic resistance. The research opens prospects for the use of such structures in current stabilizing elements with zero dissipation.

• We experimentally study timing jitter of single-photon detection by NbN superconducting strips with width ranging from 190 nm to 3 μm.

• A method has been developed for measuring the microscopic parameters of a superconductor by a tunneling probe subjected to the impact of a microwave field.

• Plasmon-assisted resonant detection of terahertz radiation by antenna-coupled graphene transistors that act as both plasmonic Fabry-Pérot cavities and rectifying elements have been demonstrated.

• We have developed an effective technology for extending the photoresponse of Si towards the IR range. Our approach is based on the use of Ag2S quantum dots (QDs) planted on the surface of Si  to create impurity states in Si band gap. The specific sensitivity of the room temperature zero-bias Si_Ag2S detector is 1011 cm√HzW-1 at 1.55μm.

• A method has been developed for protecting  against bright-light attack on superconducting nanowire single-photon detector in quantum key distribution has been developed.

• It has been demonstrated that surface magnetic disorder is normally present in oxidized TiN films.

• Our researchers have developed a simple quantum detector tomography protocol, which allows, without ambiguities, to measure the two-spot detection efficiency and extract the hot-spot interaction length of SNSPDs with unity intrinsic detection efficiency. W.

• We have conducted an experimental study of the band structure of individual carbon nanotubes (SCNTs) based on investigation of the tunneling density of states, i.e. tunneling spectroscopy.

• An experimental and theoretical research in sub-terahertz response   of graphene field-effect transistors at different temperatures has been conducted. The role of the photothermoelectric effect, p‐n junction rectification and plasmonic rectification in the sub-terahertz photoresponse of graphene field effect transistors have been determined.

• Sub-terahertz (129–450 GHz) photoresponse has been found in a device  based on single layer graphene and graphene nanoribbons with asymmetric source and drain (vanadium and gold) contacts. Vanadium forms a barrier at the graphene interface, while gold forms an Ohmic contact. We found that at low temperatures (77 K) the detector responsivity rises with the increasing frequency of the incident sub-THz radiation.

• We developed the model of internal phonon bottleneck to describe the energy exchange between the acoustically soft ultra-thin metal film and acoustically rigid substrate.

• Our researchers have experimentally demonstrated that single-photon detection can be achieved in micrometer-wide NbN bridges, with widths ranging from 0.53 to 5.15 μm and for photon wavelengths of 408 to 1550 nm.

• A comparative analysis of hot spot formation in single-photon NbC and NbN detectors has been conducted.

• We have demonstrated in a single nanophotonic device matrix integrated heterodyne nanophotonic devices in the C-band wavelength range for classical and quantum optics applications, where single-photon counting as well as high spectral resolution are required simultaneously.

• The Laboratory has developed a multipixel hot electron bolometer (HEB) receiver fabricated using silicon membrane technology.

• Spectral multiplexing and single-photon detection with hybrid superconducting nanophotonic circuits  has been demonstrated.

• Our researchers have inferred the dependence of the hot-spot relaxation time on current in niobium nitride waveguide-integrated superconducting nanowire single-photon detectors

• Sub-nanosecond light-pulse generation with waveguide-integrated carbon nanotube transducers has been experimentally demonstrated.

• Our researchers have studied the influence of the GaN buffer layer on the phonon escape time of phonon-cooled hot electron bolometers (HEBs) based on NbN material.

• The potential of a superconducting photon detector for heterodyne detection at the telecommunication wavelength has been researched.

• Superconductivity in highly disordered NbN nanowires has been studied.

• Nonequilibrium interpretation of DC properties of NbN superconducting hot electron bolometers has been attempted.

• Coherent excited states in superconductors caused by a microwave field have been studied.

• A comparison of hot-spot formation in NbC and NbN single-photon detectors has been conducted,

• Relaxation of the resistive superconducting state in boron-doped diamond films has been investigated.

• We have studied a vortex-assisted mechanism of photon counting in a superconducting nanowire single-photon detector revealed by external magnetic field.

• The Laboratory has researched the characteristics of a fast and sensitive terahertz direct detector based on a superconducting antenna-coupled hot electron bolometer.

• The characteristics of MoSi superconducting single-photon detectors in a magnetic field have been researched.

• A research of the stability of HEB mixers with microwave injection  has been completed.

• The electron-phonon energy relaxation time in thin strongly disordered titanium nitride films has been determined.

• We have studied three temperature regimes in superconducting photon detectors: Quantum, thermal and multiple phase-slips as generators of dark counts.

• Atechnology has been developed for integrating superconducting nanowires into an optical integrated circuit.

• The dependence of dark count rates in superconducting single photon detectors on the filtering effect of standard single mode optical fibers has been discovered.

• A microwave reflection readout scheme for a hot electron bolometric direct detector has been developed.

• A superconducting single-photon detector made of MoSi film  has been developed.

• The effect of the wire width on the intrinsic detection efficiency of superconducting-nanowire single-photon detectors has been investigated.

• The effect of magnetic field on the photon detection in thin superconducting meander structures has been investigated

• The possibility of heterodyne detection at near-infrared wavelengths with a superconducting NbN hot-electron bolometer mixer has been studied.

• A technology has been developed for the production of hot-electron bolometer mixers with in situ contacts.

Implemented results of research:

On the basis of the achieved scientific results in the field of superconductivity and the interaction of a superconductor with electromagnetic radiation it became possible to create a new practical device for detecting single photons in the visible and infrared range of wave lengths with an increased dynamic range and a higher operation rate. As a result, we have signed  an agreement between the Moscow State University and the industrial partner «Scontel» LLC in accordance with Decree of the Russian Federation No. 218 to perform R&D within a comprehensive project to create a high-tech production line. 

Education and career development:

• We have developed and delivered the education programs «Collective quantum phenomena», «Optic fiber systems», «Quantum optics and photonics», the lecture courses  «Collective quantum phenomena»,  «Fiber optics systems», «Quantum optics and photonics» and others for students of the Moscow Pedagogical State University and the Higher School of Economics.
• 9 Candidate of Science and 2 Doctor of Science dissertations have been prepared and defended.

Organizational and structural changes:

As a result of the work of the laboratory, in 2015 «TINFOTONIKA» Ltd, an innovation-driven company has been created, which has become a resident of Skolkovo Foundation. The company designs and manufactures integrated (including quantum) chips for modern scientific experiments and devices. Employees of the laboratory can gain experience in producing optical integrated circuits and working with those. The company provides a wide range of services from theoretical computations to producing IR and THz optical devices. It possesses a wide range of independently developed optical components and a unique technology for producing  single-photon detectors with a QE of 90 per cent on a chip. 

Other results:

Under the supervision of the employee of the Laboratory Vadim V. Kovalyuk, Candidate of Science in Physics and Mathematics, in 2022 on the grounds of the National University of Science and Technology «MISIS» the youth laboratory «Laboratory of Photonic Gas Sensors» has been created as part of the federal project «Human capital development in the interest of regions, industries and the research and technology sector» within the national project «Science and universities» that include a section called «new power industry». 

Collaborations:

• BioPhotonics Lab of the Skolkovo Institute of Science and Technology (Russia): development of microfluidic channels and classical sensors based on optic fiber.

• The laboratory also pursues a research collaboration with the following organisations:  National University of Science and Technology «MISIS», 

• National Research Nuclear University «MEPhIт», 

• Federal Research Center «Institute of Applied Physics of the Russian Academy of Sciences», 

• A. N. Tikhonov Moscow Institute of Electronics and Mathematics of the National Research University «Higher School of Economics», 

• Bauman Moscow State Technical Universe (national research university), 

• Lomonosov Moscow State University, Moscow Institute of Physics and Technology (national research university), 

• Helmholtz Moscow Research Institute of Eye Diseases (Russia), 

• German Aerospace Center, Karlrsruhe Institute of Technology, University of Münster, 

• TU Darmstadt, University of Konstanz, TU Berlin, 

• Johannes Gutenberg University Mainz, 

• Fraunhofer Institute for Applied Solid State Physics IAF (Germany), 

• Netherlands Institute for Space Research, TU Delft (Netherlands), 

• Chalmers University of Technology (Sweden), 

• Chinese Academy of Sciences, Zijinshan Astronomical Observatory (Chine PR), 

• University of Manchester, Cardiff University, 

• Royal Holloway, University of London (United Kingdom), 

• University of Waterloo (Canada), Texas A&M University, 

• University of Illinois Urbana-Champaign, 

• Massachusetts Institute of Technology (USA), 

• Tel Aviv University, Hebrew University of Jerusalem (Istael), 

• Łukasiewicz - Instytut Mikroelektroniki i Fotoniki (Польша), 

• National Institute for Materials Science (Japan), 

• French National Center for Scientific Research (France), 

• Yerevan State University (Armenia), 

• Kavli Institute of Nanoscience Delft, 

• Deutsches Zentrum für Luft-und Raumfahrt DLR, 

• Harvard–Smithsonian Center for Astrophysics.