Breakthrough for quantum networks

Up until now, trapped ions had only previously been entangled over a short distance in one and the same laboratory. Now, teams led by Tracy Northup and Ben Lanyon working at the University of Innsbruck have entangled two ions over a distance of 230 meters. The two network nodes were set up in in two laboratories at the Campus Technik.

“We sent individual photons entangled with the ions over a 500-meter fibre optic cable and superimposed them on each other, swapping the entanglement to the two ions,” says Tracy Northup in describing the experiment. “Our results show that trapped ions are a promising platform for realizing future distributed networks of quantum computers, quantum sensors and atomic clocks.” In the future, these quantum networks will be able to span entire cities and ultimately entire continents.  

Trapped ions are one of the leading systems to build quantum computers and other quantum technologies. In order to link multiple such quantum systems, interfaces are needed through which the quantum information can be transmitted. In recent years, researchers led by Tracy Northup and Ben Lanyon at the Department of Experimental Physics of the University of Innsbruck have developed a method for doing this by trapping atoms in optical cavities. In this way quantum information can be efficiently transferred to light particles. The light particles can then be sent through optical fibres to connect atoms at different locations.  

• Austria is at the cutting edge of developments in the fields of artificial intelligence (AI), cybersecurity and quantum technology. Read more about cross industry innovation in Austria.