The equivalent to a wormhole in spacetime has been created on a quantum processor. Researchers in th.
Category: quantum physics – Page 454
Wormholes — wrinkles in the fabric of spacetime that connect two disparate locations — may seem like the stuff of science fiction. But whether or not they exist in reality, studying these hypothetical objects could be the key to making concrete the tantalizing link between information and matter that has bedeviled physicists for decades.
Surprisingly, a quantum computer is an ideal platform to investigate this connection. The trick is to use a correspondence called AdS/CFT, which establishes an equivalence between a theory that describes gravity and spacetime (and wormholes) in a fictional world with a special geometry (AdS) to a quantum theory that does not contain gravity at all (CFT).
In “Traversable wormhole dynamics on a quantum processor”, published in Nature today, we report on a collaboration with researchers at Caltech, Harvard, MIT, and Fermilab to simulate the CFT on the Google Sycamore processor. By studying this quantum theory on the processor, we are able to leverage the AdS/CFT correspondence to probe the dynamics of a quantum system equivalent to a wormhole in a model of gravity. The Google Sycamore processor is among the first to have the fidelity needed to carry out this experiment.
Cooling accounts for about 15 percent of global energy consumption. Conventional clear windows allow the sun to heat up interior spaces, which energy-guzzling air-conditioners must then cool down. But what if a window could help cool the room, use no energy and preserve the view?
Tengfei Luo, the Dorini Family Professor of Energy Studies at the University of Notre Dame, and postdoctoral associate Seongmin Kim have devised a transparent coating for windows that does just that.
The coating, or transparent radiative cooler (TRC), allows visible light to come in and keeps other heat-producing light out. The researchers estimate that this invention can reduce electric cooling costs by one-third in hot climates compared to conventional glass windows.
The breakthrough could suggest a way to study ‘quantum gravity,’ the missing link between quantum physics and Einstein’s general relativity in the lab.
Using modified MRI machines, physicists may have found quantum entanglement between the heart and brain If someone were to (theoretically) throw a wrench at your head, you might be able to catch it just in time to avoid a concussion. But how? Typically, for split-second reactions, we do not consciously decide to catch.
This could help us probe into the lesser-known field of quantum gravity.
A collaborative team of researchers in the U.S. created a holographic wormhole and sent a message through it. This is the first known report of a quantum simulation of a holographic wormhole on a quantum processor.
However, the two theories are fundamentally incompatible and the holographic principle is a guide that can help us combine the two.
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Einstein’s theory of general relativity helps us to understand the physical world such as astronomical objects with high energies or matter densities. Quantum mechanics on the other hand, describes matter at atomic and subatomic scales.
A team of quantum engineers at UNSW Sydney has developed a method to reset a quantum computer—that is, to prepare a quantum bit in the ‘0’ state—with very high confidence, as needed for reliable quantum computations. The method is surprisingly simple: it is related to the old concept of ‘Maxwell’s demon’, an omniscient being that can separate a gas into hot and cold by watching the speed of the individual molecules.
“Here we used a much more modern ‘demon’—a fast digital voltmeter—to watch the temperature of an electron drawn at random from a warm pool of electrons. In doing so, we made it much colder than the pool it came from, and this corresponds to a high certainty of it being in the ‘0’ computational state,” says Professor Andrea Morello of UNSW, who led the team.
“Quantum computers are only useful if they can reach the final result with very low probability of errors. And one can have near-perfect quantum operations, but if the calculation started from the wrong code, the final result will be wrong too. Our digital ‘Maxwell’s demon’ gives us a 20x improvement in how accurately we can set the start of the computation.”
Cooling accounts for about 15 percent of global energy consumption. Conventional clear windows allow the sun to heat up interior spaces, which energy-guzzling air-conditioners must then cool down. But what if a window could help cool the room, use no energy and preserve the view?
Tengfei Luo, the Dorini Family Professor of Energy Studies at the University of Notre Dame, and postdoctoral associate Seongmin Kim have devised a transparent coating for windows that does just that (ACS Energy Letters, “High-Performance Transparent Radiative Cooler Designed by Quantum Computing”).
The coating, or transparent radiative cooler (TRC), allows visible light to come in and keeps other heat-producing light out. The researchers estimate that this invention can reduce electric cooling costs by one-third in hot climates compared to conventional glass windows.
