Simple change could boost quantum system stability 10,000-fold

14 Aug 2020454 Views

Image: © Peter Jurik/Stock.adobe.com

This week in future tech, researchers in the US have found a way to make quantum states last 10,000 times longer which is good for quantum computers.

A team of scientists at the University of Chicago’s Pritzker School of Molecular Engineering has said a new breakthrough has laid the groundwork “for exciting new avenues of research in quantum science”. Writing in Science, the team described how a simple modification allows quantum systems to stay operational – or ‘coherent’ – for 10,000 times longer than before.

While tested on a particular class of quantum systems called solid-state qubits, the team thinks it should be applicable to many other kinds of quantum systems and could potentially revolutionise quantum communication, computing and sensing.

While able to far outperform the computing power of traditional computers, quantum computers need an extremely quiet, stable space to operate as they are easily disturbed by background noise coming from vibrations, temperature changes or stray electromagnetic fields.

In effect, the University of Chicago researchers have found a way to ‘trick’ a quantum system into thinking there is no noise in its surroundings.

First author of the paper, Kevin Miao, said: “To get a sense of the principle, it’s like sitting on a merry-go-round with people yelling all around you. When the ride is still, you can hear them perfectly, but if you’re rapidly spinning, the noise blurs into a background.”

Miao added: “There are a lot of candidates for quantum technology that were pushed aside because they couldn’t maintain quantum coherence for long periods of time. Those could be re-evaluated now that we have this way to massively improve coherence.”

Chinese team finds way to boost range of quantum communication

Another area where quantum physics is set to play a major role is in communication, where quantum encrypted messages are practically impossible to decipher by a third party.

According to Space.com, a team in China has significantly improved the range in which you can send a quantum-encrypted message using a low-Earth-orbit satellite.

In testing, the team was able to send an encrypted message between ground facilities 1,200km apart, which is 12 times the distance of previous attempts.

In this experiment, pairs of entangled photons were generated aboard the satellite and then split up before being sent via two bidirectional downlinks to ground observatories in Delingha and Nanshan in China.

Because quantum computers of the future could render many traditional encryptions obsolete, quantum encryption is seen as an important topic of research and is currently being investigated by the US military.

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“A remarkable feature of the entanglement-based quantum cryptography as we demonstrated here is that such security is ensured even if the satellite is controlled by an adversary,” said Jian-Wei Pan, a quantum physicist at the University of Science and Technology of China.

South Korea debuts Covid-19-era bus shelters

Bus shelters that won’t let you in unless your body temperature is normal have been built in South Korea, according to AFP (via The Guardian). The bus stops are designed for the post-Covid-19 era to stop the spread of the disease and also come with UV disinfection lamps and hand sanitiser dispensers.

Additionally, the enclosed glass shelter is designed to keep the space air conditioned and offer protection from monsoon rain.

“We have installed all the available anti-coronavirus measures we can think of into this booth,” said Kim Hwang-yun, a district official in charge of the Smart Shelter project.

10 shelters have been built in a Seoul district at a cost of approximately $84,000 each. So far, between 300 and 400 people a day have used each booth.

Researchers identify structure of blue whirls

A team at the University of Maryland has identified the structure of intriguing ‘blue whirls’; small, spinning blue flames that produce almost no soot when they burn.

First discovered in 2016, the phenomenon has attracted a lot of attention as a potential new avenue for low-emission combustion. Now, writing in Science Advances, the researchers described using high-performance computing methods to see that blue whirls consist of three different flames: a diffusion flame, and a premixed rich and lean flame.

All of these combine into a fourth structure: a triple flame that appears as a whirling blue ring.

“The flame and flow structure revealed by the simulations serves as a fundamental base to further investigate how to create the blue whirl in a more controlled way,” said researcher Xiao Zhang. “It leads pathways to answering more complex questions.”

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Updated, 5.47pm, 14 August 2020: This article has been amended to clarify the details of the quantum communication experiment.

Colm Gorey is a senior journalist with Siliconrepublic.com

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