(IMAGE) University of Tokyo Caption A vertical electric field (green arrows) breaks the symmetry of the bilayer graphene allowing for selective control of valley. A conventional, small electrical current (purple arrow) is converted into valley current via the valley Hall effect (VHE). (The electrons in the K valley, blue, travel to the right; while the electrons in the K� valley, pink, travel to the left.) Pure valley current travels over a significant distance. At the other side of the device the valley current is converted back to charge current via the inverse valley Hall effect (IVHE) and is detected as a voltage. Credit 2015 Seigo Tarucha Usage Restrictions Journalistic use relating to this research License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.