@article{PfenningKruegerJabeenetal.2022,
  author    = {Pfenning, Andreas and Kr{\"u}ger, Sebastian and Jabeen, Fauzia and Worschech, Lukas and Hartmann, Fabian and H{\"o}fling, Sven},
  title     = {Single-photon counting with semiconductor resonant tunneling devices},
  series = {Nanomaterials},
  volume    = {12},
  journal   = {Nanomaterials},
  number    = {14},
  issn      = {2079-4991},
  doi       = {10.3390/nano12142358},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-281922},
  year      = {2022},
  abstract  = {Optical quantum information science and technologies require the capability to generate, control, and detect single or multiple quanta of light. The need to detect individual photons has motivated the development of a variety of novel and refined single-photon detectors (SPDs) with enhanced detector performance. Superconducting nanowire single-photon detectors (SNSPDs) and single-photon avalanche diodes (SPADs) are the top-performer in this field, but alternative promising and innovative devices are emerging. In this review article, we discuss the current state-of-the-art of one such alternative device capable of single-photon counting: the resonant tunneling diode (RTD) single-photon detector. Due to their peculiar photodetection mechanism and current-voltage characteristic with a region of negative differential conductance, RTD single-photon detectors provide, theoretically, several advantages over conventional SPDs, such as an inherently deadtime-free photon-number resolution at elevated temperatures, while offering low dark counts, a low timing jitter, and multiple photon detection modes. This review article brings together our previous studies and current experimental results. We focus on the current limitations of RTD-SPDs and provide detailed design and parameter variations to be potentially employed in next-generation RTD-SPD to improve the figure of merits of these alternative single-photon counting devices. The single-photon detection capability of RTDs without quantum dots is shown.},
  language  = {en}
}
@article{RothmayrGuarinCastroHartmannetal.2022,
  author    = {Rothmayr, Florian and Guarin Castro, Edgar David and Hartmann, Fabian and Knebl, Georg and Schade, Anne and H{\"o}fling, Sven and Koeth, Johannes and Pfenning, Andreas and Worschech, Lukas and Lopez-Richard, Victor},
  title     = {Resonant tunneling diodes: mid-infrared sensing at room temperature},
  series = {Nanomaterials},
  volume    = {12},
  journal   = {Nanomaterials},
  number    = {6},
  issn      = {2079-4991},
  doi       = {10.3390/nano12061024},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-267152},
  year      = {2022},
  abstract  = {Resonant tunneling diode photodetectors appear to be promising architectures with a simple design for mid-infrared sensing operations at room temperature. We fabricated resonant tunneling devices with GaInAsSb absorbers that allow operation in the 2-4 μm range with significant electrical responsivity of 0.97 A/W at 2004 nm to optical readout. This paper characterizes the photosensor response contrasting different operational regimes and offering a comprehensive theoretical analysis of the main physical ingredients that rule the sensor functionalities and affect its performance. We demonstrate how the drift, accumulation, and escape efficiencies of photogenerated carriers influence the electrostatic modulation of the sensor's electrical response and how they allow controlling the device's sensing abilities.},
  language  = {en}
}
@article{WyborskiMusiałMrowińskietal.2021,
  author    = {Wyborski, Paweł and Musiał, Anna and Mrowiński, Paweł and Podemski, Paweł and Baumann, Vasilij and Wroński, Piotr and Jabeen, Fauzia and H{\"o}fling, Sven and Sęk, Grzegorz},
  title     = {InP-substrate-based quantum dashes on a DBR as single-photon emitters at the third telecommunication window},
  series = {Materials},
  volume    = {14},
  journal   = {Materials},
  number    = {4},
  issn      = {1996-1944},
  doi       = {10.3390/ma14040759},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-228773},
  year      = {2021},
  abstract  = {We investigated emission properties of photonic structures with InAs/InGaAlAs/InP quantum dashes grown by molecular beam epitaxy on a distributed Bragg reflector. In high-spatial-resolution photoluminescence experiment, well-resolved sharp spectral lines are observed and single-photon emission is detected in the third telecommunication window characterized by very low multiphoton events probabilities. The photoluminescence spectra measured on simple photonic structures in the form of cylindrical mesas reveal significant intensity enhancement by a factor of 4 when compared to a planar sample. These results are supported by simulations of the electromagnetic field distribution, which show emission extraction efficiencies even above 18\% for optimized designs. When combined with relatively simple and undemanding fabrication approach, it makes this kind of structures competitive with the existing solutions in that spectral range and prospective in the context of efficient and practical single-photon sources for fiber-based quantum networks applications.},
  language  = {en}
}
@article{RauHeindelUnsleberetal.2014,
  author    = {Rau, Markus and Heindel, Tobias and Unsleber, Sebastian and Braun, Tristan and Fischer, Julian and Frick, Stefan and Nauerth, Sebastian and Schneider, Christian and Vest, Gwenaelle and Reitzenstein, Stephan and Kamp, Martin and Forchel, Alfred and H{\"o}fling, Sven and Weinfurter, Harald},
  title     = {Free space quantum key distribution over 500 meters using electrically driven quantum dot single-photon sources-a proof of principle experiment},
  series = {New Journal of Physics},
  volume    = {16},
  journal   = {New Journal of Physics},
  number    = {043003},
  doi       = {10.1088/1367-2630/16/4/043003},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-116760},
  year      = {2014},
  abstract  = {Highly efficient single-photon sources (SPS) can increase the secure key rate of quantum key distribution (QKD) systems compared to conventional attenuated laser systems. Here we report on a free space QKD test using an electrically driven quantum dot single-photon source (QD SPS) that does not require a separate laser setup for optical pumping and thus allows for a simple and compact SPS QKD system. We describe its implementation in our 500 m free space QKD system in downtown Munich. Emulating a BB84 protocol operating at a repetition rate of 125 MHz, we could achieve sifted key rates of 5-17 kHz with error ratios of 6-9\% and g((2))(0)-values of 0.39-0.76.},
  language  = {en}
}
@article{BraunSchneiderMaieretal.2014,
  author    = {Braun, T. and Schneider, C. and Maier, S. and Igusa, R. and Iwamoto, S. and Forchel, A. and H{\"o}fling, S. and Arakawa, Y. and Kamp, M.},
  title     = {Temperature dependency of the emission properties from positioned In(Ga)As/GaAs quantum dots},
  series = {AIP Advances},
  volume    = {4},
  journal   = {AIP Advances},
  number    = {9},
  issn      = {2158-3226},
  doi       = {10.1063/1.4896284},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-115448},
  year      = {2014},
  abstract  = {In this letter we study the influence of temperature and excitation power on the emission linewidth from site-controlled InGaAs/GaAs quantum dots grown on nanoholes defined by electron beam lithography and wet chemical etching. We identify thermal electron activation as well as direct exciton loss as the dominant intensity quenching channels. Additionally, we carefully analyze the effects of optical and acoustic phonons as well as close-by defects on the emission linewidth by means of temperature and power dependent micro-photoluminescence on single quantum dots with large pitches. (C) 2014 Author(s).},
  language  = {en}
}