Physicists have long suspected that quantum mechanics allows two observers to experience different, conflicting realities. Now they’ve performed the first experiment that proves it.
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Category: quantum physics – Page 791
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.
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China plans to develop a medium-high-earth-orbit quantum communication satellite able to provide services around the clock in the next few years, Pan Jianwei, member of the 13th National Committee of the Chinese People’s Political Consultative Conference (CPPCC), told CGTN at the press conference for the second session of the 13th CPPCC National Committee on Sunday.
When asked about the future plan for quantum communication technology, Pan said his team is planning to design a new one to supplement the Mozi satellite, which can only function at night due to interference from the sun.
The nation launched its first quantum satellite in 2016. As the world’s first quantum communication satellite, Mozi is expected to provide a technical foundation for China to build a self-developed ultra-secure communication system.
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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 quantum phenomena 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.”
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A new method for analysing the entanglement of scrambled particles could tell us how the Universe still keeps track of information contained by particles that disappear into black holes. It won’t get our quantum information back, but it might at least tell us what happened to it.
Physicists Beni Yoshida from the Perimeter Institute in Canada and Norman Yao from the University of California, Berkeley, have proposed a way to distinguish scrambled quantum information from the noise of meaningless chaos.
While the concept promises a bunch of potential applications in the emerging field of quantum technology, it’s in understanding what’s going on inside the Universe’s most paradoxical places that it might have its biggest pay-off.
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Then the 2017 DoD disclosure occurred, directly contradicting the findings in the Condon Report. We realized we had not discovered all there was to discover — not by a long shot.
AATIP succeeded where others failed simply because our understanding of the physics finally caught up to our observations.
Today, much of our government’s business is conducted behind closed doors, and mostly for good reason.
There are numerous secret programs, secret agencies, secret committees of Congress, secret laws, and even a secret courtroom. Secrecy allows our government to collect and share information, and even make decisions that otherwise could fall into enemy hands or be exploited.
Ultimately, the purpose of keeping things secret in the government is to protect sources and methods and ensure the flow and integrity of information is maintained so decision-makers can make decisions with the very best data available. It’s no surprise that governments will go to great lengths to protect the information they consider sensitive. In fact, the more sensitive information is perceived, the more it is protected.
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In my 50s, too old to become a real expert, I have finally fallen in love with algebraic geometry. As the name suggests, this is the study of geometry using algebra. Around 1637, René Descartes laid the groundwork for this subject by taking a plane, mentally drawing a grid on it, as we now do with graph paper, and calling the coordinates x and y. We can write down an equation like x + y = 1, and there will be a curve consisting of points whose coordinates obey this equation. In this example, we get a circle!
It was a revolutionary idea at the time, because it let us systematically convert questions about geometry into questions about equations, which we can solve if we’re good enough at algebra. Some mathematicians spend their whole lives on this majestic subject. But I never really liked it much until recently—now that I’ve connected it to my interest in quantum physics.
If we can figure out how to reduce topology to algebra, it might help us formulate a theory of quantum gravity.
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