A two-atom quantum duet

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. North or south pole 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 (one 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.

"Like a phalanx, the two atoms were able to protect each other from external influences, better than on their own." said Dr. Yujeong Bae, researcher at QNS and first author of the study. "In that way the entangled quantum states we created were not affected by environmental disruptions such as magnetic field noise".

"This is a significant development that shows how we can engineer and sense the states of atoms. This allows us to explore their possibility to be used as quantum bits for future quantum information processing.", added Prof. Andreas Heinrich, director of QNS. In future experiments, the researchers plan to build even more sophisticated structures in order to explore and improve the quantum properties of single atoms and nanostructures.

Research paper

Related Links
Institute for Basic Science
Space Technology News - Applications and Research

Tweet

Thanks for being there;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.

SpaceDaily Monthly Supporter
$5+ Billed Monthly

paypal only

SpaceDaily Contributor
$5 Billed Once

credit card or paypal

Unlocking the secrets of metal-insulator transitions
Upton NY (SPX) Nov 09, 2018
By using an x-ray technique available at the National Synchrotron Light Source II (NSLS-II), scientists found that the metal-insulator transition in the correlated material magnetite is a two-step process. The researchers from the University of California Davis published their paper in the journal Physical Review Letters. NSLS-II, a U.S. Department of Energy (DOE) Office of Science user facility located at Brookhaven National Laboratory, has unique features that allow the technique to be applied with st ... read more