Related papers: Spectral analysis for cascade-emission-based quant…
Quantum information science attempts to exploit capabilities from the quantum realm to accomplish tasks that are otherwise impossible in the classical domain [1]. Although sufficient conditions have been formulated for the physical…
Quantum communication is a method that offers efficient and secure ways for the exchange of information in a network. Large-scale quantum communication (of the order of 100 km) has been achieved; however, serious problems occur beyond this…
We theoretically investigate the spectral property of biphoton state from the cascade emissions from a Doppler-broadened atomic ensemble. This biphoton state is spontaneously created in the four-wave-mixing process. The upper transition of…
The cascade-emitted biphotons generated from the alkali metal atomic ensembles are an excellent entanglement resource which enables long-distance quantum communication. The communication of quantum information between distant locations can…
We investigate superradiant cascade emissions from an atomic ensemble driven by two-color classical fields. The correlated pair of photons (signal and idler) is generated by adiabatically driving the system with large-detuned light fields…
A quantum repeater at telecommunications wavelengths with long-lived atomic memory is proposed, and its critical elements are experimentally demonstrated using a cold atomic ensemble. Via atomic cascade emission, an entangled pair of 1530…
We present a detailed analysis of a new robust quantum repeater architecture building on the original DLCZ protocol [L.M. Duan \textit{et al.}, Nature (London) \textbf{414}, 413 (2001)]. The new architecture is based on two-photon…
By implementing a quantum repeater protocol, our aim in this paper is the production of entanglement between two two-level atoms locating far from each other. To make our model close to experimental realizations, the atomic and field…
We investigate the spectral properties of the biphoton state from the cascade emissions of cold atomic ensembles, which composes of a telecommunication photon (signal) followed by an infrared one (idler) via four-wave mixing.\ With…
In this thesis, we investigate the quantum mechanical interaction of light with matter in the form of a gas of ultracold atoms: the atomic ensemble. We present a theoretical analysis of two problems, which involve the interaction of…
We theoretically investigate the spectral entanglement of a multiphoton source generated from the cascade emissions in the cascaded cold atomic ensembles.\ This photon source is highly directional, guaranteed under the four-wave mixing…
In this Letter we propose a robust quantum repeater architecture building on the original DLCZ protocol [L.M. Duan \textit{et al.}, Nature \textbf{414}, 413 (2001)]. The architecture is based on two-photon Hong-Ou-Mandel-type interference…
We propose and investigate a scheme for the steady-state emission of quantum-correlated, telecom-band light from a single multilevel atom. By appropriately tuning the frequency of a pair of lasers, a two-photon transition is continually…
We analyze how the performance of a quantum-repeater network depends on the protocol employed to distribute entanglement, and we find that the choice of repeater-to-repeater link protocol has a profound impact on communication rate as a…
For the development of long-distance quantum networks, sources of single photons and entangled photon pairs emitting in the low-loss wavelength region around 1550 nm are a crucial building block. Here we show that quantum dot devices based…
Duan-Lukin-Cirac-Zoller (DLCZ)-based multimodequantum networks rely on efficient spatial-to-fiber coupling, yetenvironmental perturbations compromise this performance. Wedevelop a cascaded adaptive feedback control system integratedinto the…
A quantum repeater node is presented based on trapped ions that act as single photon emitters, quantum memories and an elementary quantum processor. The node's ability to establish entanglement across two 25 km-long optical fibers…
We present a quantum repeater protocol using atomic ensembles, linear optics and single-photon sources. Two local 'polarization' entangled states of atomic ensembles $u$ and $d$ are generated by absorbing a single photon emitted by an…
We demonstrate the first experimental realization of cascaded resonance fluorescence over a 64-meter propagation delay time between two spatially and temporally independent ensembles of laser-cooled Cesium atoms coupled to an optical…
Based on the interaction between a three-level system and a microtoroidal resonator, we present a scheme for long-distance quantum communication in which entanglement generation with near 0.5 success probability and swaps can be implemented…