‘Spooky action at a distance’ demonstrated in single-particle quantum experiment for first time

A team of scientists have for the first time successfully demonstrated the non-local collapse of a particle’s wave function in an experiment using a single particle.

Using homodyne detectors to measure the particle, and quantum tomography to map the effect of those measurements, the scientists, from Griffith University and the University of Tokyo, were able to verify single-particle quantum entanglement an unusual form of entanglement that could prove invaluable for quantum computing and communications.

While quantum entanglement usually refers to two particles that are bound by opposing spins, the directions of which will only be set when they are observed, single particles can also be entangled, meaning their wave function – ie the equation that defines their likely location and behaviour – can cover any distance.

In other words, a single entangled particle can only be in one place at a given time, but it can be located over a very large distance. When the particle is measured, the wave function will instantly collapse to a set location.

Professor Howard Wiseman at the Centre for Quantum Dynamics. Image courtesy of Griffith University.

Professor Howard Wiseman at the Centre for Quantum Dynamics. Image courtesy of Griffith University.

This was demonstrated by the scientists, who split a single photon between their labs in Japan and Australia, but was previously regarded as an unlikely phenomenon by Albert Einstein.

Almost 90 years ago, he used single-particle entanglement as evidence that quantum mechanics was incorrect, deriding non-local wave function collapse as “spooky action at a distance”.

“Einstein never accepted orthodox quantum mechanics and the original basis of his contention was this single-particle argument,” explained Professor Howard Wiseman, director of Griffith University’s Centre for Quantum Dynamics.

“This is why it is important to demonstrate non-local wave function collapse with a single particle.”

While taking issue with quantum mechanics, Einstein proposed an alternative hypothesis for the particle’s behaviour.

“Einstein’s view was that the detection of the particle only ever at one point could be much better explained by the hypothesis that the particle is only ever at one point, without invoking the instantaneous collapse of the wave function to nothing at all other points.”

Although this alternative theory seems more acceptable to the human brain, Wiseman and his colleagues have shown it to be incorrect.

“Rather than simply detecting the presence or absence of the particle, we used homodyne measurements enabling one party to make different measurements and the other, using quantum tomography, to test the effect of those choices,” he explained.

“Through these different measurements, you see the wave function collapse in different ways, thus proving its existence and showing that Einstein was wrong.”

The research was published today in Nature Communications.


Journal reference: Fuwa M, Takeda S, Zwierz M, Wiseman HM, Furusawa A. Experimental proof of nonlocal wavefunction collapse for a single particle using homodyne measurements. Nature Communications 06 March 2015. doi:10.1038/ncomms7665.


 

Robot takes first steps towards building artificial lifeforms

A robot equipped with sophisticated AI has successfully simulated the creation of artificial lifeforms, in a key first step towards the eventual goal of creating true artificial life.

The robot, which was developed by scientists at the University of Glasgow, was able to model the creation of artificial lifeforms using unstable oil-in-water droplets. These droplets effectively played the role of living cells, demonstrating the potential of future research to develop living cells based on building blocks that cannot be found in nature.

Significantly, the robot also successfully predicted their properties before they were created, even though this could not be achieved using conventional physical models.

The robot, which was designed by Glasgow University’s Regius Chair of Chemistry, Professor Lee Cronin, is driven by machine learning and the principles of evolution.

It has been developed to autonomously create oil-in-water droplets with a host of different chemical makeups and then use image recognition to assess their behaviour.

Using this information, the robot was able to engineer droplets to have different properties­. Those which were found to be desirable could then be recreated at any time, using a specific digital code.

“This work is exciting as it shows that we are able to use machine learning and a novel robotic platform to understand the system in ways that cannot be done using conventional laboratory methods, including the discovery of ‘swarm’ like group behaviour of the droplets, akin to flocking birds,” said Cronin.

“Achieving lifelike behaviours such as this are important in our mission to make new lifeforms, and these droplets may be considered ‘protocells’ – simplified models of living cells.”

One of the oil droplets created by the robot

The research, which is published today in the journal PNAS, is one of several research projects being undertaken by Cronin and his team within the field of artificial lifeforms.

While the overarching goal is moving towards the creation of lifeforms using new and unprecedented building blocks, the research may also have more immediate potential applications.

The team believes that their work could also have applications in several practical areas, including the development of new methods for drug delivery or even innovative materials with functional properties.

Mac spyware stole millions of user images

A criminal case brought against a man from Ohio, US has shed more light on a piece of Mac malware, dubbed Fruitfly, that was used to surreptitiously turn on cameras and microphones, take and download screenshots, log keystrokes, and steal tax and medical records, photographs, internet searches, and bank transactions from users.

Source: Ars Technica

Drone swarm attack strikes Russian military bases

Russia's Ministry of Defence claims its forces in Syria were attacked a week ago by a swarm of home-made drones. According to Russia's MoD Russian forces at the Khmeimim air base and Tartus naval facility "successfully warded off a terrorist attack with massive application of unmanned aerial vehicles (UAVs)"

Source: Science Alert

Las Vegas strip club employs robot strippers

A Las Vegas strip club has flown in robot strippers from London to 'perform' at the club during CES. Sapphire Las Vegas strip club managing partner Peter Feinstein said that he employed the robots because the demographics of CES have changed and the traditional female strippers aren’t enough to lure a crowd to the club anymore.

Source: Daily Beast

GM to make driverless cars without steering wheels or pedals by 2019

General Motors has announced it plans to mass-produce self-driving cars without traditional controls like steering wheels and pedals by 2019. “It’s a pretty exciting moment in the history of the path to wide scale [autonomous vehicle] deployment and having the first production car with no driver controls,” GM President Dan Ammann told The Verge.

Source: The Verge

Russia-linked hackers "Fancy Bears" target the IOC

Following Russia's ban from the upcoming 2018 Winter Olympics, the Russia-linked hacking group "Fancy Bears" has published a set of apparently stolen emails, which purportedly belong to officials from the International Olympic Committee, the United States Olympic Committee, and third-party groups associated with the organisations.

Source: Wired

Scientists discover ice cliffs on Mars

Using images provided by the Mars Reconnaissance Orbiter, scientists have described how steep cliffs, up to 100 meters tall, made of what appears to be nearly pure ice indicate that large deposits of ice may also be located in nearby underground deposits. The discovery has been described as “very exciting” for potential human bases.

Source: Science Mag