Workshop on the engineering challenges of Quantum Technologies in Space
Quantum Technologies are regarded as high-priority and strategic at the European Space Agency.
The presentation will sketch how quantum technologies development activities are coordinated and supported across the different ESA Directorates and programmes.
In recent years, significant effort has been focused on developing quantum technologies for use ‘in the field’ resulting in a remarkable reduction in SWaP for portable quantum-based apparatus. The use of quantum devices in space poses yet more engineering challenges over terrestrial devices. I will present some of these challenges and discuss design considerations to overcome them, and improve the lifespan of quantum tech-based space missions.
A discussion on the engineering challenges of making electronic systems work reliably in the space environment, and the wide range of options and approaches that can be used to mitigate them for different styles of mission.
We will provide an overview of qtlabs' activities in space-based QKD systems. Building on pioneering work in long-distance free-space QKD and performing down links from a quantum satellite, qtlabs has developed expertise and products for space QKD over the last years. This concerns development of quantum sources for space, mission design and QKD protocols, as well as optical ground stations. Connections to relevant QKD missions and the collaboration with international partner will be highlighted.
Quantum technologies promise new capabilities for communication, sensing, and computing. Quantum system performance is generally improved through networking, and a “global quantum internet” is seen as a key infrastructure to realize this promise. Spacecraft quantum technologies will serve an important role in future quantum networking architectures. I will review active, upcoming, and planned JPL space missions that deploy quantum technologies in space, with an emphasis on quantum-networking systems.
This presentation will address current research and development of a low-SWaP laser-cooled single Sr+ ion clock system focused on space clock applications
There has been recent dramatic global investment in quantum technologies, which now often harness laser-cooled atom traps. Such traps yield orders of magnitude longer measurement times and concomitant accuracy enhancements promised within the small physical footprint already demonstrated in warm atomic systems. Six-beam magneto-optical traps (MOTs) are ubiquitous in cold atomic physics experiments, delivering dense and cold atomic vapours. Grating MOTs (GMOTs), used either in- or ex-vacuo, enable simple and robust MOT generation with a single input laser beam. We present recent Strathclyde GMOT-based experimental results including a truly compact vacuum cell, a clock etc [1], and highlight GMOT developments in other groups. Prospects for utilising reflective and transmissive micro-fabricated planar optics for single-input-beam high-stability optical lattices [1] and Fresnel optical waveguides will also be discussed [2].
[1] https://eqop.phys.strath.ac.uk/atom-optics/grating-mots/
[2] https://eqop.phys.strath.ac.uk/atom-optics/qt-atom-interferometers/
We present a cold-atom pulsed optically pumped (POP) microwave atomic clock based on an additively manufactured loop-gap-resonator microwave cavity and grating magneto-optical trap (GMOT). Additive manufacturing allows for almost arbitrary electrode geometries, more difficult to produce with traditional manufacturing. This approach is also highly scalable and requires minimal assembly. The use of a GMOT allows for a significant simplification of the optical requirements for laser cooling and reduces the optical access requirements of the cavity body. In this demonstration we use a single laser to trap and cool a sample of 87Rb atoms, prepare them in the clock-state and read out the resulting populations after microwave interaction. A Ramsey type interrogation scheme is employed resulting in a short-term stability of <2e-11 τ-1/2. This work is a novel approach towards cold-atom frequency standards for the next generation of compact time keeping.
To gain better understanding of the upper atmospheric dynamics requires more accurate determination of the mass density distribution in the thermosphere. Improved measurements of drag, by means of satellite accelerometery, can be used to more precisely determine this distribution. In addition, atmospheric drag in Low Earth Orbit (LEO) is particularly of interest for climate modelling, weather forecasting and satellite orbit prediction. RAL Space and the University of Birmingham are developing a Cold Atom Space Payload Atmospheric Drag Mission (CASPA-ADM). The aim of the project, supported by the UK Centre for Earth Observation Instrumentation (CEOI), is to develop a technology demonstrator based on Cold Atom Interferometry (CAI) to take sensitive measurements of atmospheric drag. The underlying CAI technology has been previously flown on the Chinese Space Station, the International Space Station, and in sounding rockets. However, it has not yet been used as the fundamental sensor technology in a free flight space mission. The team is producing a space-suitable accelerometer that can be embedded in small satellites such as 16U CubeSats and are addressing the engineering challenges associated with space qualification and miniaturisation, while keeping the performance level of systems with larger Size, Weight and Power (SWaP)
Poster will give an overview of three current projects undergoing at Fraunhofer CAP. One project is based on satellite based Quantum Key Distribution (QKD) encoded communication to be packaged in a compact, robust and commercially-viable form. More details in a second project on photon entanglement with different sources for space applications. Finally, a quick overview of the project in collaboration with Craft Prospect in designing a compact, low-loss optical telescope for QKD.
The decoy state technique in quantum key distribution (QKD) has been proven as the most optimal strategy to counter photon number splitting (PNS) attacks. In the asymptotic limit of running the experiment an infinite time, it was shown that 2-decoy outperforms 1-decoy protocol. However, it was also showed that 1-decoy reached higher key rates than 2-decoy for finite block sizes except for short (below 79 km) and long (above 290km) distances. This analysis was performed for a simple channel loss. Here, we present a comparison for a free space channel. Our numerical simulation toolkit (SatQuMa) was used to compare the two decoy methods in a satellite scenario. Our research may provide implications in future satellite QKD missions.
The development of cubic optical cavities for high TRL low SWaP stabilization of laser light for applications in the space sector, such as fundamental physics, Earth observation and future navigation, will be presented.
In the drive to develop cold-atom quantum technologies, compact vacuum systems are key to enabling quantum sensing for real world applications. These vacuum systems not only have to be reduced in size, weight, and power compared to their traditional counterparts, but face other challenges.
Eliminating active pumping addresses both size and power, but introduces the issue of helium gas permeation as passive vacuum pumping techniques do not remove noble gases. Here we present a centilitre-scale vacuum cell, constructed from low helium permeable materials, with an integrated grating magneto-optical trap optic. This small vacuum cell can form the basis of a compact cold-atom source, when used in conjunction with a quadrupole
magnetic field and a single laser beam. This is step towards cold-atom sources being an off-the-shelf component, much like lasers are sources of coherent light.
Recent developments in space quantum communications have highlighted the role robust quantum sources onboard small satellites and CubeSats could play in enabling trustless QKD and helping to implement a global quantum communication network. A major step in this direction would be to perform satellite-to-ground QKD using entanglement-based protocols such as BBM92 where correlations remove the need for additional trusted devices to ensure security. This presentation will focus on the expanding capabilities of QKD satellite applications and the impact a commercially available low SWaP entanglement-based source could have in next-generation quantum communications and beyond.
Space-based quantum networks require highly efficient quantum links between ground systems on Earth and orbiting spacecraft. A test system at JPL emulated timing desynchronization and polarization rotation driven by the relative motion between Earth and a spacecraft. These dynamics are introduced to a single-photon communication system and addressed using compensation systems. The system under development at JPL is planned to be deployed at the Optical Communication Telescope Laboratory in Wrightwood, CA, and coupled to the 1-m aperture primary mirror in support of near-term quantum communications space missions.
We will discuss a method based on coincidence detection to increase the key rate in a prepare and measure protocol. The proposed protocol provides higher key rate compared to the most popular BB84 and Decoy State QKD protocols.
We study the security of prepare-and-measure satellite-based quantum key distribution (QKD) in restricted eavesdropping scenarios where Eve has limited access to the transmitted signal by Alice. An artefact of such an assumption is the possibility of having bypass channels, those which are not accessible to Eve, but may not necessarily be characterized by the users either. This creates interesting scenarios for analyzing QKD security. Here, we present generic bounds on the key rate in the presence of bypass channels and apply them to continuous-variable QKD protocols with Gaussian encoding with direct and reverse reconciliation. We find regimes of operation in which the above restrictions on Eve can considerably improve system performance. We also develop customised bounds for several protocols in the BB84 family and show that, in certain regimes, even the simple protocol of BB84 with weak coherent pulses is able to offer positive key rates at high channel losses, which would otherwise be impossible under an unrestricted Eve. Our work opens up new security frameworks for spaceborne quantum communications systems.