Structured light is a fancy way to describe patterns or pictures of light, but deservedly so as it promises future communications that will be both faster and more secure.
Quantum mechanics has come a long way during the past 100 years but still has a long way to go. In AVS Quantum Science, from AIP Publishing, researchers from the University of Witwatersrand in South Africa review the progress being made in using structured light in quantum protocols to create a larger encoding alphabet, stronger security and better resistance to noise.
READ THE PAPER: http://aip.scitation.org/doi/full/10.1116/1.5112027
“What we really want is to do quantum mechanics with patterns of light,” said co-author Professor Andrew Forbes from the School of Physics at the University of the Witwatersrand. “By this, we mean that light comes in a variety of patterns that can be made unique – like our faces.”
Since patterns of light can be distinguished from each other, they can be used as a form of alphabet. “The cool thing is that there are, in principle at least, an infinite set of patterns, so an infinite alphabet is available,” he said.
Traditionally, quantum protocols have been implemented with the polarisation of light, which has only two values – a two-level system with a maximum information capacity per photon of just 1 bit. But by using patterns of light as the alphabet, the information capacity is much higher. Also, its security is stronger, and the robustness to noise (such as background light fluctuations) is improved.
“Patterns of light are a route to what we term high-dimensional states,” Forbes said. “They are high dimensional because many patterns are involved in the quantum process. Unfortunately, the toolkit to manage these patterns is still underdeveloped and requires a lot of work.”
The quantum science community has made many recent noteworthy advances, both in the science and derived technologies. For example, entanglement swapping has now been demonstrated with spatial modes of light, a core ingredient in a quantum repeater, while the means to securely communicate between nodes is now possible through high-dimensional quantum key distribution protocols. Together they bring us a little bit closer to a fast and secure quantum network.
Similarly, the construction of exotic multi-party high-dimensional states for quantum computer has been realised, as has enhanced resolution in ghost imaging (produced by combining light from two light detectors). Yet it remains challenging to break beyond the ubiquitous two photons in two dimensions for full control of multiple photons entangled in high dimensions.
“We know how to create and detect photons entangled in patterns,” said Forbes. “But we don’t really have good control on getting them from one point to another, because they distort in the atmosphere and in optical fibre. And we don’t really know how to efficiently extract information from them. It requires too many measurements at the moment,” he added.
Forbes and his co-author, Isaac Nape helped pioneer the use of hybrid states – another big advance. Old textbook quantum mechanics was done with polarisation.
“It turns out that many protocols can be efficiently implemented with simpler tools by combining patterns with polarisation for the best of both worlds,” said Forbes. “Rather than two dimensions of patterns, hybrid states allow access to multidimensional states, for example, an infinite set of two-dimensional systems. This looks like a promising way forward to truly realize a quantum network based on patterns of light.”
The article, “Quantum mechanics with patterns of light: Progress in high dimensional and multi-dimensional entanglement with structured light,” authored by Forbes and Nape can be accessed at http://aip.scitation.org/doi/full/10.1116/1.5112027.
GoFundMe hits R9bn in donations for people and causes
The world’s largest social fundraising platform has announced that Its community has made more than 120-million donations
GoFundMe this week released its annual Year in Giving report, revealing that its community has donated more than 120-million times, raising over $9-billion for people, causes, and organisations since the company’s founding in 2010.
In a letter to the GoFundMe community, CEO Rob Solomon emphasised how GoFundMe witnesses not only the good in people worldwide, but their generosity and their action every day.
“As we enter a new decade, GoFundMe is committed to spreading compassion and empathy through our platform,” said Solomon in the letter. “Together, we can bring more good into the world and unlock the power of global giving.”
The GoFundMe giving community continues to grow with both repeat donors and new donors. In fact, nearly 60% of donors were new this year. After someone makes a donation, they continue to engage with the community and give to multiple causes. In fact, one passionate individual donated 293 times to 234 different fundraisers in this past year alone. Donations are made every second, ranging from $5 to $50,000. This year, more than 40% of donations were under $50.
GoFundMe continues to be a mirror of current events across the globe. This year, young changemakers started the Fridays for Futuremovement to fight climate change, which led to a 60% increase in fundraiser descriptions mentioning ‘climate change’. Additionally, the community rallied together to support one another during natural disasters like Hurricane Dorian and the California wildfires, where thousands of fundraisers were started to help those in need.
The report includes a snapshot of giving trends from the year based on global GoFundMe data. It also includes company milestones from 2019, such as launching the company’s non-profit and advocacy arm, GoFundMe.org, and introducing GoFundMe Charity, which provides enterprise software with no subscription fees or contracts to charities of every size.
Highlights from GoFundMe’s 2019 Year in Giving report include:
- Global giving trends and data
- Top 10 most generous countries
- Top 10 most generous U.S. states and cities
- Biggest moments in 2019
To view the entire report, visit: www.gofundme.com/2019
For users, in-car touchscreens ever more useless
As touchscreens become more commonplace, the gulf of perceived differences in the performance of these features between cars and other devices (such as mobile and in-home) has become wider. A new report from the In-Vehicle UX (IVX) group at Strategy Analytics has investigated car owners’ satisfaction with their on-board touchscreens. Long hamstrung by poor UX and extended production cycles, in-car touchscreens are seen by car users and buyers as lagging behind the experience offered by touchscreens outside the car. As such, consumer satisfaction has continued to slide in China and Europe, while reaching historic lows in the US.
Surveying consumers in the US, Western Europe, and China via web-survey, key report findings include:
- Difficult text entry and excessive fingerprint smudging are common complaints among all car owners.
- Because touchscreens have reached market saturation in the US, satisfaction with in-car screens has tailed off significantly.
- However, touchscreens remain a relatively newer phenomenon in many car models in Western Europe (compared with the US) and thus their limitations are less prominent in the minds of car owners.
- Overall touchscreen satisfaction fell for the fifth straight year in China, indicating a growing impatience for in-car UX to match UX found elsewhere in the consumer electronics space.
Derek Viita, Senior Analyst and report author, says, “Part of the issue with fingerprint smudging is the angle at which in-car touchscreens are installed – they make every fingerprint increasingly visible.
“Fingerprint smudging is an issue across all touchscreen-based consumer electronics. But in most form factors and especially mobile devices, consumers can quite easily adjust their viewing angle. This is not always the case with fixed in-car screens.”
Says Chris Schreiner, Director, Syndicated Research UXIP, “Although hardware quality certainly figures in many of the usual complaints car owners have about their screens, it is not the sole factor. Cockpit layout and UI design can play important roles in mitigating some issues with in-car touchscreens.”