Quantum uplinks to Earth-orbiting satellites will necessitate single-photon detector technology that is robust to space radiation for the lifetime of the satellite. In this study, we experimentally assessed the effect of such radiation on a targetted selection of candidate detectors, with a focus on their impact to quantum key distribution. We then attempted to mitigate these effects, using thermal controls including deep cooling (during operation) and high-temperature annealing. Our results show that such techniques can maintain useful performance significantly beyond the one-year baseline lifetime.

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This paper describes work I mentioned earlier. We successfully demonstrated quantum key distribution with signals transmitted from a ground station to a receiver on board a flying airplane. Our receiver (which is significantly upgraded in comparison to our prior truck demonstration) was designed and largely custom-built to have a clear path to flight on a satellite. Our demonstration illustrates the viability of such a payload.

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Some context:

• Ministers Bains and Garneau celebrate $80.9 million for the Canadian Space Agency.
• Canada's support will help Waterloo launch quantum research into space.
• Statement on Government of Canada support for quantum space innovation.

I've been involved with the QEYSSat project, working on studies and prototypes, for the last 6 years. It's wonderful to see it selected as one of the two projects to receive funding, thereby allowing it to become an actual mission. Very exciting times!

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September of 2016 was a busy month for a few reasons, one of these being the two weeks I was (with the rest of our IQC team) in Smiths Falls outside Ottawa conducting trials of our prototype quantum key distribution system. Ultimately this involved transmitting quantum signals from our ground-station quantum source to our receiver on a flying NRC aircraft—quite successfully, I might add. In the intervening time to now (and modulo one vacation to Australia and New Zealand) we wrote-up our results into a paper, the pre-print of which recently appeared on the arXiv.

At the same time (not coincidentally) an article about our work appeared in the Canadian newspaper The Globe and Mail—page 1 on Dec. 21, in our region—as well as the Waterloo Region Record (pg. 2, Dec. 22). You can read the online edition of the article.

So that's neat.

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I use Debian with KDE's Plasma desktop environment. I usually track Debian's testing repository, but often I like to upgrade the version of KDE packages installed to more recent versions in the unstable repository. My preferred way:

sudo aptitude --visual-preview -t unstable install ~i~mkde

The action tends to be independent of anything else, but that's easy enough to work around—update per usual before running.

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For some time, I've been happily using Unison in conjunction with my Android phone's USB mass storage function to synchronize files between my phone and my desktop. It was simple: I'd plug in my phone with USB and enable the SD card to be used as a mass storage device, then mount it in Linux and run Unison as if the phone was a local folder (with appropriate tweaks to support the FAT filesystem).

Alas, my phone was getting on in years (or months, as it is in tech), and with support long dropped and capacity nigh exhausted, I had to upgrade. With my new phone I've been promoted to the “new hotness” that is Android 6 Marshmallow, but one of the functions that was dropped along the way was the ability to expose the SD card as mass storage over USB. Admittedly it wasn't a perfect solution, requiring unmounting the SD card within Android itself while using it over USB, but the current approaches introduce their own deficiencies. In any case, my previous workflow wasn't going to work anymore.

Of course I didn't want to stop using Unison, or have Unison re-copy everything, or even merely re-scan everything. I [...]

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