Scientists have proven for the very first time that one of the most fundamental problems of particle and quantum physics is mathematically unsolvable.
In short, they show that regardless of how no matter how perfectly we can mathematically describe a material on the microscopic level, we are never going to be able to predict its macroscopic behavior. Never.
The work was published in Nature.
The UK’s first quantum accelerometer for navigation has been demonstrated by a team from Imperial College London and M Squared.
Most navigation today relies on a global navigation satellite system (GNSS), such as GPS, which sends and receives signals from satellites orbiting the Earth. The quantum accelerometer is a self-contained system that does not rely on any external signals.
This is particularly important because satellite signals can become unavailable due to blockages such as tall buildings, or can be jammed, imitated or denied – preventing accurate navigation. One day of denial of the satellite service would cost the UK £1 billion.
Scientists are planning to create a network in the Chicago area tapping the principles of quantum physics. The idea is to prove that quantum physics could provide the basis for an unhackable internet.
This, they say, could have wide-ranging impact on communications, computing and national security.
The quantum network development, supported by the US Department of Energy (DOE), will stretch between the DOE’s Argonne National Laboratory and Fermi National Acceleratory Laboratory, a connection that is said will be the longest in the world to send secure information using quantum physics.
Researchers at the Center for Quantum Nanoscience (QNS) within the Institute for Basic Science (IBS) achieved a major breakthrough in shielding the quantum properties of single atoms on a surface. The scientists used the magnetism of single atoms, known as spin, as a basic building block for quantum information processing. The researchers could show that by packing two atoms closely together they could protect their fragile quantum properties much better than for just one atom.
The spin is a fundamental quantum mechanical object and governs magnetic properties of materials. In a classical picture, the spin often can be considered like the needle of a compass. The north or south poles of the needle, for example, can represent spin up or down. However, according to the laws of quantum mechanics, the spin can also point in both directions at the same time. This superposition state is very fragile since the interaction of the spin with the local environment causes dephasing of the superposition. Understanding the dephasing mechanism and enhancing the quantum coherence are one of the key ingredients toward spin-based quantum information processing.
In this study, published in the journal Science Advances in November 9, 2018, QNS scientists tried to suppress the decoherence of single atoms by assembling them closely together. The spins, for which they used single titanium atoms, were studied by using a sharp metal tip of a scanning tunneling microscope and the atoms’ spin states were detected using electron spin resonance. The researchers found that by bringing the atoms very close together (1 million times closer than a millimeter), they could protect the superposition states of these two magnetically coupled atoms 20 times longer compared to an individual atom.
