Educação matemática pela arte
Gusmão, Lucimar Donizete
2013-08-28
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7 records were found.
Comment: 12 pages, 6 figures; Fig. 5(a) is replaced
Single Photon Detectors (SPD) are fundamental to quantum optics and quantum
information. Superconducting Nanowire SPDs (SNSPD) [1] provide high performance
in terms of quantum efficiency (QE), dark count rate (DCR) and timing jitter
[2], but have limited maximum count rate (MCR) when operated as a free-running
mode (FM) detector [3, 4]. However, high count rates are needed for many
applications like quantum computing [5] and communication [6], and laser
ranging [7]. Here we report the first operation of SNSPDs in a gated mode (GM)
that exploits a single photon triggered latching phenomenon to detect photons.
We demonstrate operation of a large active area single element GM-SNSPD at
625MHz, one order of magnitude faster than its FM counterpart. Contrary to
FM-SNSPDs, the MCR in GM can be pushed to GHz range without a compromise on the...
Single Photon Detectors are integral to quantum optics and quantum
information. Superconducting Nanowire based detectors exhibit new levels of
performance, but have no accepted quantum optical model that is valid for
multiple input photons. By performing Detector Tomography, we improve the
recently proposed model [M.K. Akhlaghi and A.H. Majedi, IEEE Trans. Appl.
Supercond. 19, 361 (2009)] and also investigate the manner in which these
detectors respond nonlinearly to light, a valuable feature for some
applications. We develop a device independent model for Single Photon Detectors
that incorporates this nonlinearity.
Comment: 3 pages, 6 figures, submitted to APL
Comment: Expanded discussions, updated references. 9 pages, 8 figures
We have experimentally compared the critical current, dark count rate and
photo-response of 100nm wide superconducting nanowires with different bend
designs. Enhanced critical current for nanowires with optimally rounded bends,
and thus with no current crowding, are observed. Furthermore, we find that the
optimally designed bend significantly reduces the dark counts without
compromising the photo-response of the device. The results can lead to major
improvements in superconducting nanowire single photon detectors.
