A5039111042- Quantum Information and Cryptography
- Semiconductor Quantum Structures and Devices
- Quantum Mechanics and Applications
- Quantum optics and atomic interactions
- Quantum Computing Algorithms and Architecture
- Semiconductor Lasers and Optical Devices
- Nonlinear Optical Materials Studies
- Advanced Fluorescence Microscopy Techniques
- Cell Image Analysis Techniques
- bioluminescence and chemiluminescence research
- Quantum Dots Synthesis And Properties
- Nanoplatforms for cancer theranostics
- Advanced Semiconductor Detectors and Materials
- Photonic and Optical Devices
- Mechanical and Optical Resonators
Sapienza University of Rome
2020-2023
Johannes Kepler University of Linz
1986-2019
Quantum key distribution---exchanging a random secret relying on quantum mechanical resource---is the core feature of secure networks. Entanglement-based protocols offer additional layers security and scale favorably with repeaters, but stringent requirements set photon source have made their use situational so far. Semiconductor-based emitters are promising solution in this scenario, ensuring on-demand generation near-unity-fidelity entangled photons record-low multi-photon emission, latter...
Abstract Entanglement-based quantum key distribution can enable secure communication in trusted node-free networks and over long distances. Although implementations exist both fiber free space, the latter approach is often considered challenging due to environmental factors. Here, we implement a protocol during daytime for first time using dot source. This technology presents advantages terms of narrower spectral bandwidth—beneficial filtering out sunlight—and negligible multiphoton emission...
Abstract The realization of a functional quantum repeater is one the major research goals in long-distance communication. Among different approaches that are being followed, relying on memories interfaced with deterministic emitters considered as most promising solutions. In this work, we focus hardware to implement memory-based quantum-repeater schemes rely semiconductor dots (QDs) for generation polarization entangled photons. Going through relevant figures merit related efficiency photon...
Quantum networks play a crucial role in distributed quantum information processing, enabling the establishment of entanglement and communication among distant nodes. Fundamentally, with independent sources allow for new forms nonlocality, beyond paradigmatic Bell’s theorem. Here we implement simplest such networks—the bilocality scenario—in an urban network connecting different buildings fully scalable hybrid approach. Two using technologies—a dot nonlinear crystal—are used to share photonic...
We investigate the effect of multiphoton emission on polarization-entangled photon pairs from a coherently driven quantum dot by comparing state tomography and second-order autocorrelation measurements as function excitation power. observe that relative (absolute) probability is low...
Transmission and reflectivity measurements on thin epitaxial samples of Pb1-xMnxTe (x<or=0.02) are analysed in the vicinity absorption edge using a novel numerical procedure which takes full account internal interference dispersion. The spectral dependence coefficient is well described by two-band k.p model. resulting energy gap increases up to 40% for x=2% at low temperatures as compared PbTe. From far infrared investigations, no significant influence x found lattice dynamical properties.
We show that multiphoton thiol–ene polymerized structures comprise unreacted thiol moieties, which can be used for postpolymerization gold metallization. Some of the groups located at surface are not involved in reactions and, therefore, serve as nucleation seeds synthesis ∼50 nm sized nanoislands. Additionally, we nanoislands immobilization fluorescent molecules. observed a significant enhancement fluorescence signal on nanoisland-functionalized polymer when compared to structured polymers...
Two-photon resonant excitation of the biexciton-exciton cascade in a quantum dot generates highly polarization-entangled photon pairs near-deterministic way. However, ultimate level achievable entanglement is still debated. Here, we observe impact laser-induced AC-Stark effect on emission spectra and entanglement. For increasing pulse-duration/lifetime ratios pump powers, decreasing values concurrence are recorded. Nonetheless, additional contributions required to fully account for observed...
A quantum-light source that delivers photons with a high brightness and degree of entanglement is fundamental for the development efficient entanglement-based quantum-key distribution systems. Among all possible candidates, epitaxial quantum dots are currently emerging as one brightest sources highly entangled photons. However, optimization both requires different technologies difficult to combine in scalable manner. In this work, we overcome challenge by developing novel device consisting...
Quantum key distribution (QKD) is at the heart of future secure quantum communication networks as it can enhance security classical strategies. Although prepare-and-measure protocols are most widely used in practical applications, entangled-based QKD promising for further improving degree and developing free-trusted node networks. However, free-space link implementations single photon transmission suffer daylight operations few works have been demonstrated this regime. Furthermore, air has...
Quantum networks play a crucial role for distributed quantum information processing, enabling the establishment of entanglement and communication among distant nodes. Firstly, we use coherently driven dot to experimentally demonstrate modified Ekert key distribution protocol with two channel approaches: both 250-m-long single-mode fiber in free-space, connecting buildings within campus Sapienza University Rome. Second, included an independent SPDC source construct hybrid network (quantum...
Multiphoton emission limits applications of probabilistic entangled photon sources in quantum information technologies. Using dots under various conditions resonant two-photon excitation, we demonstrate that entanglement is unaffected by multipair emission.
During recent years, quantum dots have become an increasingly established source of highly entangled photons <sup>1</sup>. The main motivation for the development this technology has resided in expectation that a resonantly driven emitter can offer path towards on-demand photon pair generation <sup>2</sup>. In fact, state-of-the-art sources relying on spontaneous parametric down-conversion intrinsically suffer from multipair emission at high rates, which causes tradeoff between brightness...