|
Korneev, A., Divochiy, A., Tarkhov, M., Minaeva, O., Seleznev, V., Kaurova, N., et al. (2008). New advanced generation of superconducting NbN-nanowire single-photon detectors capable of photon number resolving. In J. Phys.: Conf. Ser. (Vol. 97, 012307 (1 to 6)).
Abstract: We present our latest generation of ultrafast superconducting NbN single-photon detectors (SSPD) capable of photon-number resolving (PNR). We have developed, fabricated and tested a multi-sectional design of NbN nanowire structures. The novel SSPD structures consist of several meander sections connected in parallel, each having a resistor connected in series. The novel SSPDs combine 10 μm × 10 μm active areas with a low kinetic inductance and PNR capability. That resulted in a significantly reduced photoresponse pulse duration, allowing for GHz counting rates. The detector's response magnitude is directly proportional to the number of incident photons, which makes this feature easy to use. We present experimental data on the performances of the PNR SSPDs. The PNR SSPDs are perfectly suited for fibreless free-space telecommunications, as well as for ultrafast quantum cryptography and quantum computing.
|
|
|
Milostnaya, I., Korneev, A., Tarkhov, M., Divochiy, A., Minaeva, O., Seleznev, V., et al. (2008). Superconducting single photon nanowire detectors development for IR and THz applications. J. Low Temp. Phys., 151(1-2), 591–596.
Abstract: We present our progress in the development of superconducting single-photon detectors (SSPDs) based on meander-shaped nanowires made from few-nm-thick superconducting films. The SSPDs are operated at a temperature of 2–4.2 K (well below T c ) being biased with a current very close to the nanowire critical current at the operation temperature. To date, the material of choice for SSPDs is niobium nitride (NbN). Developed NbN SSPDs are capable of single photon counting in the range from VIS to mid-IR (up to 6 μm) with a record low dark counts rate and record-high counting rate. The use of a material with a low transition temperature should shift the detectors sensitivity towards longer wavelengths. We present state-of-the art NbN SSPDs as well as the results of our recent approach to expand the developed SSPD technology by the use of superconducting materials with lower T c , such as molybdenum rhenium (MoRe). MoRe SSPDs first were made and tested; a single photon response was obtained.
|
|
|
Korneev, A., Divochiy, A., Tarkhov, M., Minaeva, O., Seleznev, V., Kaurova, N., et al. (2008). Superconducting NbN-nanowire single-photon detectors capable of photon number resolving. In Supercond. News Forum.
Abstract: We present our latest generation of ultra-fast superconducting NbN single-photon detectors (SSPD) capable of photon-number resolving (PNR). The novel SSPDs combine 10 μm x 10 μm active area with low kinetic inductance and PNR capability. That resulted in significantly reduced photoresponse pulse duration, allowing for GHz counting rates. The detector’s response magnitude is directly proportional to the number of incident photons, which makes this feature easy to use. We present experimental data on the performance of the PNR SSPDs. These detectors are perfectly suited for fibreless free-space telecommunications, as well as for ultra-fast quantum cryptography and quantum computing.
|
|
|
Zhang, J., Slysz, W., Verevkin, A., Okunev, O., Chulkova, G., Korneev, A., et al. (2003). Response time characterization of NbN superconducting single-photon detectors. IEEE Trans. Appl. Supercond., 13(2), 180–183.
Abstract: We report our time-resolved measurements of NbN-based superconducting single-photon detectors. The structures are meander-type, 10-nm thick, and 200-nm wide stripes and were operated at 4.2 K. We have shown that the NbN devices can count single-photon pulses with below 100-ps time resolution. The response signal pulse width was about 150 ps, and the system jitter was measured to be 35 ps.
|
|
|
Okunev, O., Chulkova, G., Milostnaya, I., Antipov, A., Smirnov, K., Morozov, D., et al. (2008). Registration of infrared single photons by a two-channel receiver based on fiber-coupled superconducting single-photon detectors. In I. A. Sukhoivanov, V. A. Svich, & Y. S. Shmaliy (Eds.), Proc. SPIE (Vol. 7009, 70090V (1 to 8)). SPIE.
Abstract: Single-photon detectors (SPDs) are the foundation of all quantum communications (QC) protocols. Among different classes of SPDs currently studied, NbN superconducting SPDs (SSPDs) are established as the best devices for ultrafast counting of single photons in the infrared (IR) wavelength range. The SSPDs are nanostructured, 100 μm2 in total area, superconducting meanders, patterned by electron lithography in ultra-thin NbN films. Their operation has been explained within a phenomenological hot-electron photoresponse model. We present the design and performance of a novel, two-channel SPD receiver, based on two fiber-coupled NbN SSPDs. The receivers have been developed for fiber-based QC systems, operational at 1.3 μm and 1.55 μm telecommunication wavelengths. They operate in the temperature range from 4.2 K to 2 K, in which the NbN SSPDs exhibit their best performance. The receiver unit has been designed as a cryostat insert, placed inside a standard liquid-heliumstorage dewar. The input of the receiver consists of a pair of single-mode optical fibers, equipped with the standard FC connectors and kept at room temperature. Coupling between the SSPD and the fiber is achieved using a specially designed, precise micromechanical holder that places the fiber directly on top of the SSPD nanostructure. Our receivers achieve the quantum efficiency of up to 7% for near-IR photons, with the coupling efficiency of about 30%. The response time was measured to be < 1.5 ns and it was limited by our read-out electronics. The jitter of fiber-coupled SSPDs is < 35 ps and their dark-count rate is below 1s-1. The presented performance parameters show that our single-photon receivers are fully applicable for quantum correlation-type QC systems, including practical quantum cryptography.
|
|