title: Quantum dot single-photon switches of resonant tunneling current for discriminating-photon-number detection.
abstract: Low-noise single-photon detectors that can resolve photon numbers are used to monitor the operation of quantum gates in linear-optical quantum computation. Exactly 0, 1 or 2 photons registered in a detector should be distinguished especially in long-distance quantum communication and quantum computation. Here we demonstrate a photon-number-resolving detector based on quantum dot coupled resonant tunneling diodes (QD-cRTD). Individual quantum-dots (QDs) coupled closely with adjacent quantum well (QW) of resonant tunneling diode operate as photon-gated switches- which turn on (off) the RTD tunneling current when they trap photon-generated holes (recombine with injected electrons). Proposed electron-injecting operation fills electrons into coupled QDs which turn "photon-switches" to "OFF" state and make the detector ready for multiple-photons detection. With proper decision regions defined, 1-photon and 2-photon states are resolved in 4.2 K with excellent propabilities of accuracy of 90% and 98% respectively. Further, by identifying step-like photon responses, the photon-number-resolving capability is sustained to 77 K, making the detector a promising candidate for advanced quantum information applications where photon-number-states should be accurately distinguished.
authors: 1] National Laboratory for Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai 200083, PR China [2] Key Laboratory of Polar Materials and Devices, Ministry of Education, East China Normal University, Shanghai 200241, PR China.
authors: Qianchun
authors: Q
authors: Weng
authors: 1] State Key Laboratory of Surface Physics, Key Laboratory of Micro and Nano Photonic Structures (Ministry of Education) and Institute of Advanced Materials, Fudan University, Shanghai 200433, PR China [2] Collaborative Innovation Center of Advanced Microstructures, Fudan University, Shanghai 200433, PR China.
authors: Zhenghua
authors: Z
authors: An
authors: National Laboratory for Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai 200083, PR China.
authors: Bo
authors: B
authors: Zhang
authors: National Laboratory for Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai 200083, PR China.
authors: Pingping
authors: P
authors: Chen
authors: National Laboratory for Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai 200083, PR China.
authors: Xiaoshuang
authors: X
authors: Chen
authors: Key Laboratory of Polar Materials and Devices, Ministry of Education, East China Normal University, Shanghai 200241, PR China.
authors: Ziqiang
authors: Z
authors: Zhu
authors: National Laboratory for Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai 200083, PR China.
authors: Wei
authors: W
authors: Lu