- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Repeater-enhanced distributed quantum sensing based on continuous-variable multipartite entanglement
摘要： Entanglement is a unique resource for quantum-enhanced applications. When employed in sensing, shared entanglement between distributed quantum sensors enables a substantial gain in the measurement sensitivity in estimating global parameters of the quantum sensor network. Loss incurred in the distribution of entanglement, however, quickly dissipates the measurement-sensitivity advantage enjoyed by the entangled quantum sensors over sensors supplied with local quantum resources. Here we present a viable approach to overcome the entanglement-distribution loss and show that the measurement sensitivity enabled by entangled quantum sensors beats that afforded by the optimum local resource. Our approach relies on noiseless linear amplifiers (NLAs) to serve as quantum repeaters. We show that, unlike the outstanding challenge of building quantum repeaters to suppress the repeaterless bound for quantum key distribution, NLA-based quantum repeaters for distributed quantum sensing are realizable by available technology. As such, distributed quantum sensing would become an application instance that benefits from quantum repeaters.
关键词： quantum repeaters,distributed quantum sensing,entanglement,quantum sensing,noiseless linear amplifiers
更新于2025-09-23 15:22:29
-
[IEEE 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Munich, Germany (2019.6.23-2019.6.27)] 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Quantum Storage of Frequency-Multiplexed Heralded Single Photons
摘要： Quantum memories for light are important devices in quantum information science, in particular for applications such as quantum networks and quantum repeaters [1]. It has been predicted that multimode quantum memories able to store independently multiple modes would greatly help the scaling of quantum networks by decreasing the entanglement generation time between remote quantum nodes [1]. Current research focuses mostly on time multiplexing in rare-earth doped crystals and in spatial multiplexing in atomic gases. Beyond these demonstrations, rare-earth doped crystals, thanks to their large inhomogeneous broadening, represent a unique quantum system which could also add another degree of freedom for multiplexing, the storage of multiple frequency modes [2]. In this contribution, we report on the first demonstration of quantum storage of a frequency multiplexed single photon into a laser-written waveguide integrated in a Pr3+:Y2SiO5 crystal. The great advantage of using a confined waveguide for this task is that the power required to prepare the quantum memory is strongly reduced due to the increased light-matter interaction in the waveguide. This enables simultaneous preparation of several memories at different frequencies, with a moderate laser power.
关键词： quantum repeaters,Quantum memory,single photons,quantum networks,frequency multiplexing
更新于2025-09-11 14:15:04
-
[IEEE 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Munich, Germany (2019.6.23-2019.6.27)] 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Towards Storage of Sub-Megahertz Single Photons in Gradient Echo Memory
摘要： Quantum repeaters are foundational to establishing the long distance quantum communication channels necessary to create a global communication network. A quantum memory capable of storing optical quantum states is an integral component of the quantum repeater. A wide variety of mechanisms for implementing an optical quantum memory have been investigated, ranging from simple optical delay lines to complicated photon echo schemes. The scheme of interest here is the gradient echo memory (GEM). GEM has been demonstrated to be one of the most efficient memory schemes to date, with up to 87% recall efficiency and up to 1ms coherence time when performed in a cold atomic ensemble of 87Rb atoms. Until now, GEM has only been investigated with weak coherent pulses as no single photon source met the demanding spectral requirements of the memory protocol. In particular, it requires sub-megahertz linewidth photons at the atomic transitions of 87Rb. A compatible source has been developed utilising cavity-enhanced spontaneous parametric downconversion (SPDC) generating photons with a bandwidth of 429 ± 10 kHz. This is, to our knowledge, the narrowest single photon bandwidth from SPDC to date. Integration with this source enables single photon storage for the first time using GEM and allows for its single photon level characteristics to finally be investigated. Single-photon quantum memory opens up the prospect of using the system as a quantum optical gate. Storing multiple single photon states simultaneously in the quantum memory can potentially give rise to photon-photon interactions due to cross phase modulation.
关键词： single photon source,gradient echo memory,quantum repeaters,sub-megahertz linewidth photons,quantum memory
更新于2025-09-11 14:15:04