decoherence tagged posts

The universe may be trapped in its own comfort zone, and a researcher in the College of Engineering and Computer Science has helped explain why it cannot seem to leave. A new study suggests the universe could be locked into its current state by the same kinds of quantum effects that scientists study when trying to preserve fragile information inside a quantum computer.

The paper, titled “Cosmic Lockdown: When Decoherence Saves the Universe from Tunneling,” has been accepted for publication in the Journal of Cosmology and Astroparticle Physics.

It was written by Gregory Kaplanek, a postdoctoral researcher working in the lab of Jason Pollack, an assistant professor in the Department of Electrical Engineering and Computer Science, along with four c...

Researchers from RIKEN and QuTech — a collaboration between TU Delft and the Netherlands Organisation for Applied Scientific Research (TNO) — have achieved a key milestone toward the development of a fault-tolerant quantum computer. They were able to demonstrate a two-qubit gate fidelity of 99.5 percent — higher than the 99 percent considered to be the threshold for building fault-tolerant computers — using electron spin qubits in silicon, which are promising for large-scale quantum computers as the nanofabrication technology for building them already exists. This study was published in Nature.

The world is currently in a race to develop large-scale quantum computers that could vastly outperform classical computers in certain area...

Fast-forwarding quantum calculations skips past the time limits imposed by decoherence, which plagues today’s machines. A new algorithm that fastforwards simulations could bring greater use ability to current and near-term quantum computers, opening the way for applications to run past strict time limits that hamper many quantum calculations.

“Quantum computers have a limited time to perform calculations before their useful quantum nature, which we call coherence, breaks down,” said Andrew Sornborger of the Computer, Computational, and Statistical Sciences division at Los Alamos National Laboratory, and senior author on a paper announcing the research...

Jonathan G. Richens, John H. Selby, and Sabri W. Al-Safi. “Entanglement is Necessary for Emergent Classicality in All Physical Theories.” Physical Review Letters. DOI: 10.1103/PhysRevLett.119.080503

Is entanglement really necessary for describing the physical world, or is it possible to have some post-quantum theory without entanglement? In a new study, physicists have mathematically proved that any theory that has a classical limit-meaning that it can describe our observations of the classical world by recovering classical theory under certain conditions-must contain entanglement...