Quantum correlations between single telecom photons and a multimode on-demand solid-state quantum memory

Quantum correlations between long-lived quantum memories and telecom photons that can propagate with low loss in optical fibers are an essential resource for the realization of large-scale quantum information networks. Significant progress has been realized in this direction with atomic and solid-state systems. Here, we demonstrate quantum correlations between a telecom photon and a multimode ondemand solid state quantum memory. This is achieved by mapping a correlated single photon onto a spin collective excitation in a Pr 3+ :Y 2 SiO 5 crystal for a controllable time. The stored single photons are generated by cavity-enhanced spontaneous parametric down-conversion and heralded by their partner photons at telecom wavelength. These results represent the first demonstration of a multimode on-demand solid state quantum memory for external quantum states of light. They provide an important resource for quantum repeaters and pave the way for the implementation of quantum information networks with distant solid state quantum nodes.We acknowledge financial support by the ERC Starting Grant QuLIMA, by the Spanish Ministry of Economy and Competitiveness (MINECO) and Fondo Europeo de Desarrollo Regional (FEDER) (FIS2015-69535-R), by MINECO Severo Ochoa through Grant No. SEV-2015-0522 and through the Ph.D. Fellowship Program (for A. S.), by AGAUR via 2014 SGR 1554, by Fundació Cellex, and by CERCA Programme/Generalitat de Catalunya

Simulating quantum repeater strategies for multiple satellites

A global quantum repeater network involving satellite based links is likely to have advantages over fiber based networks in terms of long distance communication, since the photon losses in vacuum scale only polynomially with the distance compared to the exponential losses in optical fibers. To simulate the performance of such networks, we have introduced a scheme of large scale event based Monte Carlo simulation of quantum repeaters with multiple memories that can faithfully represent loss and imperfections in these memories. In this work, we identify the quantum key distribution rates achievable in various satellite and ground station geometries for feasible experimental parameters. The power and flexibility of the simulation toolbox allows us to explore various strategies and parameters, some of which only arise in these more complex, multi satellite repeater scenarios. As a primary result, we conclude that key rates in the kHz range are reasonably attainable for intercontinental quantum communication with three satellites, only one of which carries a quantum memor

Catheter-related bacteremia due to Kocuria rosea in a patient undergoing peripheral blood stem cell transplantation

BACKGROUND: Micrococcus species may cause intracranial abscesses, meningitis, pneumonia, and septic arthritis in immunosuppressed or immunocompetent hosts. In addition, strains identified as Micrococcus spp. have been reported recently in infections associated with indwelling intravenous lines, continuous ambulatory peritoneal dialysis fluids, ventricular shunts and prosthetic valves. CASE PRESENTATION: We report on the first case of a catheter-related bacteremia caused by Kocuria rosea, a gram-positive microorganism belonging to the family Micrococcaceae, in a 39-year-old man undergoing peripheral blood stem cell transplantation due to relapsed Hodgkin disease. This uncommon pathogen may cause opportunistic infections in immunocompromised patients. CONCLUSIONS: This report presents a case of Kocuria rosea catheter related bacteremia after stem cell transplantation successfully treated with vancomycin and by catheter removal

AEDGE: Atomic Experiment for Dark Matter and Gravity Exploration in Space

We propose in this White Paper a concept for a space experiment using cold atoms to search for ultra-light dark matter, and to detect gravitational waves in the frequency range between the most sensitive ranges of LISA and the terrestrial LIGO/Virgo/KAGRA/INDIGO experiments. This interdisciplinary experiment, called Atomic Experiment for Dark Matter and Gravity Exploration (AEDGE), will also complement other planned searches for dark matter, and exploit synergies with other gravitational wave detectors. We give examples of the extended range of sensitivity to ultra-light dark matter offered by AEDGE, and how its gravitational-wave measurements could explore the assembly of super-massive black holes, first-order phase transitions in the early universe and cosmic strings. AEDGE will be based upon technologies now being developed for terrestrial experiments using cold atoms, and will benefit from the space experience obtained with, e.g., LISA and cold atom experiments in microgravity. This paper is based on a submission (v1) in response to the Call for White Papers for the Voyage 2050 long-term plan in the ESA Science Programme. ESA limited the number of White Paper authors to 30. However, in this version (v2) we have welcomed as supporting authors participants in the Workshop on Atomic Experiments for Dark Matter and Gravity Exploration held at CERN: ({\tt https://indico.cern.ch/event/830432/}), as well as other interested scientists, and have incorporated additional material

Terrestrial Very-Long-Baseline Atom Interferometry:Workshop Summary

This document presents a summary of the 2023 Terrestrial Very-Long-Baseline Atom Interferometry Workshop hosted by CERN. The workshop brought together experts from around the world to discuss the exciting developments in large-scale atom interferometer (AI) prototypes and their potential for detecting ultralight dark matter and gravitational waves. The primary objective of the workshop was to lay the groundwork for an international TVLBAI proto-collaboration. This collaboration aims to unite researchers from different institutions to strategize and secure funding for terrestrial large-scale AI projects. The ultimate goal is to create a roadmap detailing the design and technology choices for one or more km-scale detectors, which will be operational in the mid-2030s. The key sections of this report present the physics case and technical challenges, together with a comprehensive overview of the discussions at the workshop together with the main conclusions

Toward a RESTful Information-Centric Web of Things: A Deeper Look at Data Orientation in CoAP

The information-centric networking (ICN) paradigm offers replication of autonomously verifiable content throughout a network, in which content is bound to names instead of hosts. This has proven beneficial in particular for the constrained IoT. Several approaches, the most prominent of which being Named Data Networking, propose access to named content directly on the network layer. Independently, the IETF CoAP protocol group started to develop mechanisms that support autonomous content processing and in-network storage. In this paper, we explore the emerging CoAP protocol building blocks and how they contribute to an information-centric network architecture for a data-oriented RESTful Web of Things. We discuss design options and measure characteristic performances of different network configurations, which deploy CoAP proxies and OSCORE content object security, and compare with NDN. Our findings indicate an almost continuous design space ranging from plain CoAP at the one end to NDN on the other. On both ends - -ICN and CoAP - -we identify protocol features and aspects whose mutual transfer potentially improves design and operation of the other

A solid state spin-wave quantum memory for photonic time-Bin qubits

Rare-earth (RE) doped crystals are promising candidates as quantum memories as they offer coherence properties comparable to those of atomic systems, but free of the drawbacks deriving from the atomic motion. The research on RE doped crystals quantum memories has been so far mostly focused on the mapping of quantum bits to optical collective excitations using the atomic frequency comb (AFC) or the gradient echo memory protocols [1-3]. However, this leads to short lived and mostly pre-determined storage. In this contribution, we report the first solid state spin-wave optical quantum memory with on-demand read-out. We also demonstrate the first spin-wave storage of time-bin qubits with conditional fidelities higher than for classical memories [4]