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Significant advancements have been made in quantum computing, with major international companies like Google and IBM now providing quantum computing services via the cloud. Nevertheless, quantum computers are not yet capable of addressing issues that arise when conventional computers hit their performance ceilings. This limitation is primarily the availability of qubits or quantum bits, i.e., the basic units of quantum information, is still insufficient.

One of the reasons for this is that bare qubits are not of immediate use for running a quantum algorithm. While the binary bits of customary computers store information in the form of fixed values of either 0 or 1, qubits can represent 0 and 1 at one and the same time, bringing probability as to their value into play. This is known as quantum superposition.

This makes them very susceptible to external influences, which means that the information they store can readily be lost. In order to ensure that quantum computers supply reliable results, it is necessary to generate a genuine entanglement to join together several physical qubits to form a logical qubit. Should one of these physical qubits fail, the other qubits will retain the information. However, one of the main difficulties preventing the development of functional quantum computers is the large number of physical qubits required.

A superfluid vortex controlled in a lab is helping physicists learn more about the behavior of black holes.

A whirlpool generated in helium cooled to just a fraction above absolute zero mimics the gravitational environment of these objects to such high precision that it’s giving unprecedented insight into how they drag and warp the space-time around them.

“Using superfluid helium has allowed us to study tiny surface waves in greater detail and accuracy than with our previous experiments in water,” explains physicist Patrik Švančara of the University of Nottingham in the UK, who led the research.

Quantum information theorists have turned Wigner’s friend into a powerful set of thought experiments for testing the plausibility of physical assumptions we make when we share information. These elaborated thought experiments involve multiple participants in multiple labs, entangled quantum states between friends and real-life entangled photon experiments to smoke out what our classical assumptions are.

Is there a fork in the road, classical or quantum? To stick with the classical interpretation that says Wigner’s friend involves two inconsistent descriptions of one state of affairs produces paradoxes. The quantum perspective implies there are descriptions of two different states of affairs. The first is intuitive but ends up in a contradiction, the other is less intuitive, but consistent. Quantum friendship means never having to say you’re sorry for your use of the formalism.

Robert P Crease is a professor (click link below for full bio), Jennifer Carter is a lecturer and Gino Elia is a PhD student, all in the Department of Philosophy, Stony Brook University, US.

Simulations of an elusive carbon molecule that leaves diamonds in the dust for hardness may pave the way to creating it in a lab.

Known as the eight-atom body-centered cubic (BC8) phase, the configuration is expected to be up to 30 percent more resistant to compression than diamond – the hardest known stable material on Earth.

Physicists from the US and Sweden ran quantum-accurate molecular-dynamics simulations on a supercomputer to see how diamond behaved under high pressure when temperatures rose to levels that ought to make it unstable, revealing new clues on the conditions that could push the carbon atoms in diamond into the unusual structure.

Scientists around the world work hard to rinse quantum systems for noise, which may disturb the function of tomorrow’s powerful quantum computers. Researchers from the Niels Bohr Institute (NBI) have found a way to use noise to process quantum information. This raises the performance of the quantum computing unit, the qubit.

An international collaboration led by scientists at the Niels Bohr Institute (NBI), University of Copenhagen, has demonstrated an alternative approach. Their method allows to use noise to process quantum information. As a result, the performance of the fundamental quantum computing unit of information, the qubit, is increased by 700 percent.

The results were published recently in the journal Nature Communications.