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Scientists Have “Reversed Time” Inside A Quantum Computer, And The Implications Are Huge

Time: it’s constantly running out and we never have enough of it. Some say it’s an illusion, some say it flies like an arrow. Well, this arrow of time is a big headache in physics. Why does time have a particular direction? And can such a direction be reversed?

A new study, published in Scientific Reports, is providing an important point of discussion on the subject. An international team of researchers has constructed a time-reversal program on a quantum computer, in an experiment that has huge implications for our understanding of quantum computing. Their approach also revealed something rather important: the time-reversal operation is so complex that it is extremely improbable, maybe impossible, for it to happen spontaneously in nature.

As far as laws of physics go, in many cases, there’s nothing to stop us going forward and backward in time. In certain quantum systems it is possible to create a time-reversal operation. Here, the team crafted a thought experiment based on a realistic scenario.

Prototype watch uses your body to prevent hacking of wearables and implants

We’re used to the security risks posed by someone hacking into our computers, tablets, and smartphones, but what about pacemakers and other implanted medical devices? To help prevent possible murder-by-hacker, engineers at Purdue University have come up with a watch-like device that turns the human body into its own network as a way to keep personal technology private.

Quantum physicists succeed in controlling energy losses and shifts

Quantum computers need to preserve quantum information for a long time to be able to crack important problems faster than a normal computer. Energy losses take the state of the qubit from one to zero, destroying stored quantum information at the same time. Consequently, scientists all over the globe have traditionally worked to remove all sources of energy loss—or dissipation—from these machines.

Dr. Mikko Mottonen from Aalto University and his research team have taken a different approach. “Years ago, we realized that quantum computers actually need dissipation to operate efficiently. The trick is to have it only when you need it,” he explains.

In their paper to be published on 11 March 2019 in Nature Physics, scientists from Aalto University and the University of Oulu demonstrate that they can increase the dissipation rate by a factor of thousand in a high-quality superconducting resonator on demand—such resonators are used in prototype quantum computers.

Using quantum measurements to fuel a cooling engine

Researchers at the University of Florence and Istituto dei Sistemi Complessi, in Italy, have recently proved that the invasiveness of quantum measurements might not always be detrimental. In a study published in Physical Review Letters, they showed that this invasive quality can actually be exploited, using quantum measurements to fuel a cooling engine.

Michele Campisi, one of the researchers involved in the study, has been studying for several years. In his recent work, he investigated whether quantum phenomena can impact the thermodynamics of nanoscopic devices, such as those employed in quantum computers.

“Most colleagues in the field were looking at coherence and entanglement while only few were looking at another at genuine quantum phenomenon, i.e., the quantum measurement process,” Campisi told Phys.org. “Those studies suggested that you need to accompany measurements with feedback control, as in Maxwell’s demon, in order to exploit their potential. I started thinking about it, and eureka—since quantum measurements are very invasive, they are accompanied by energy exchanges, hence can be used to power engines without the need to do feedback control.”

A student accidentally created a rechargeable battery that could last 400 years

There’s no better example of that than a 2016 discovery at the University of California, Irvine, by doctoral student Mya Le Thai. After playing around in the lab, she made a discovery that could lead to a rechargeable battery that could last up to 400 years. That means longer-lasting laptops and smartphones and fewer lithium ion batteries piling up in landfills.

Researchers close in on physics’ holy grail with ‘super’ breakthrough

A team of scientists in the US has brought us a huge step closer to a superconductor capable of working at room temperature.

If humankind were to find a way to construct a large-scale superconductor that could work at room temperature, the way our energy grids and computers are built – and many other areas of daily life – would be fundamentally changed.

The phenomenon is the lack of electrical resistance and is observed in many materials when they are cooled below temperatures of around −180 degrees Celsius, making them rather limited in their application. However, a team from George Washington University in the US has revealed something that could help us finally reach what is one of the most sought-after achievements in modern physics.