University of Science and Technology of China

Guangcan Guo

Zhengfu Han

Deyong He

Zheng Zhou

Chuanfeng Li

Zongquan Zhou

Shuang Wang

Zhenqiang Yin

Wei Feng Chen

Chao Liu

Yang Yang

Yonggang Wang

Jiaxuan Li

Yuanguanjie Fan

Fengyu Lu

Wei Chen

Tao Zhang

Xiaofan Mo

Bing Zhu

Yuhu Li

Dajun Huang

Xiao Liu

Peiyun Li

Tao Tu

Yu Ma

A quantum key distribution system is provided, including: a sending terminal, a measurement terminal, a receiving terminal, and at least one polarization controller. The sending terminal is configured to generate a quantum optical signal and receive a detection result. The measurement terminal includes a beam splitter and two single-photon detectors, the beam splitter is configured to generate two measurement optical signals based on the quantum optical signal, and the two single-photon detectors are configured to generate the detection result. The receiving terminal is configured to receive the detection result. The at least one polarization controller is provided in the sending terminal, the measurement terminal or the receiving terminal, and performs a polarization processing on the quantum optical signal or the detection result using a target transmittance matrix determined based on the detection result, so as to obtain a polarized quantum optical signal or a polarized detection result.

Quantum key distribution system

Provided is a quantum sensor based on a rare-earth-ion doped optical crystal, having: a rare-earth-ion doped optical crystal; a low temperature providing unit, which provides a low temperature operating environment to the rare-earth-ion doped optical crystal; a constant magnetic field generation unit, which applies a constant magnetic field to the rare-earth-ion doped optical crystal; a light field generation unit, which provides a light field performing optical pumping on the rare-earth-ion doped optical crystal to prepare the rare-earth-ions in an initial spin state, and a light field for exciting Raman scattering of the rare-earth-ion doped optical crystal; a pulsed magnetic field generation unit, which applies a pulsed magnetic field perpendicular to the constant magnetic field to the rare-earth-ion doped optical crystal to make the rare-earth-ion doped optical crystal generate a spin echo; and a heterodyne Raman scattering light field detection and analysis unit, which detects and analyzes a Raman scattering light field radiated from the rare-earth-ion doped optical crystal. Further provided are uses of this quantum sensor for magnetic field sensing and electric field sensing as well as a sensing method.

Quantum sensor based on rare-earth-ion doped optical crystal and use thereof

A pulsed electron paramagnetic resonance spectrometer comprises: a microwave excitation generating unit for generating at least one microwave pulse; a microwave conducting unit comprising a resonant cavity and a microwave transmission line for transmitting microwaves, wherein the microwave transmission line is connected between the microwave excitation generating unit and the resonant cavity, and the resonant cavity is for placing a sample; a cryostat and magnet unit comprising a cryostat that performs ultra-low temperature cooling for the microwave resonant cavity, the microwave transmission line being disposed to pass through the cryostat and connected to the resonant cavity; the cryostat and magnet unit further comprises a magnet that provides a resonance test magnetic field around the sample, the resonant cavity being disposed in a room temperature gap of the magnet. The device of the present disclosure characteristics in ultra-low sample temperature (0.1 Kelvin) and is fully functional and easy to operate.

Pulsed electron paramagnetic resonance spectrometer

The present invention utilizes a high-speed serial data transceiver to generate two high-speed electric pulse signals. After passing through a gain network, the signals are used for driving an electro-optic phase modulator (PM) so as to realize phase modulation of photon signals. The present invention may directly use a high-speed digital signal to realize a four-phase modulation function needed by the BB84 quantum key distribution protocol without using a digital to analog converter or an analog switch. This can prevent modulation rate from being restricted by links including digital-to-analog conversion, switching of the analog and the like. A dual-electrode electro-optic phase modulator scheme can also effectively reduce requirements for amplitude of a modulation driving signal, thus facilitating realization of high-speed phase modulation, which meets requirements of quantum key distribution.

Photon phase modulating system

The invention relates to a polarization-controlled encoding method, encoder and quantum key distribution system, which is characterized in that polarization maintaining light path or 90 degree rotation Faraday mirror are used inside the encoder to keep the polarization of the output pulses same, and that in the quantum key distribution system employing the polarization-controlled encoder the pulse emitted from transmitter is unidirectional-transmitted to receiver and then quantum key distribution is implemented using interference in the pulses according to the quantum key distribution protocol. The quantum key distribution system using the polarization-controlled encoder of the invention has the ability of avoiding the wiretapping to transmitter, receiver and quantum channel. Detection units each of which separates reversed photon from other photons are added at the out port of the transmitter and the in port of receiver, respectively, so that Trojan horse is prevented from entering and photons with phase modulated information are prevented from leaving the safe area in receiver. Unconditionally safe key distribution can be accomplished by using the quantum key distribution system of the invention.

Polarization-controlled encoding method, encoder, and quantum key distribution system

An addressing method of quantum network and a quantum network router are disclosed. There are at least three nodes in the network. The method comprises steps of: appointing an address serial number for every node; sending photon signals with different wavelength from one node to other nodes, wherein the signal source wavelength and node address are regarded as an addressing badge; determining, by every node, the source of signal according to the addressing badge of received photon signals. Quantum network router comprises a photon signal allocator including N sets of optical components, one end of every optical component is mix-wavelength interface, and the other end includes separate wavelength interfaces; an external interface comprising mix-wavelength interfaces of optical components, separate wavelength interfaces of different optical components, which transmit the same wavelength signals, connect one to one. Using this invention can realize quantum communication in deed, includes quantum cryptographic key distribution, quantum network transmission, namely generalized quantum communication, and compose quantum computer addressing bus or quantum computer network, etc.

Addressing method of quanta network and quanta network router

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Anhui, China

Guangcan Guo