News:
The tunneling of a particle through a barrier is one of the most fascinating quantum phenomena. The motion taking place under the barrier, in a region forbidden by classical mechanics, is the subject of intense debate. Many experiments aim at measuring the time taken by the particle to go through the tunnel. Here, we take a completely different direction, revealing the influence of the dynamics under the barrier on the motion of the outgoing particle. Our approach combines two key elements: the barrier is chiral—its structure cannot be superimposed on its mirror image—and it rotates in time. Specifically, our barrier holds the electrons inside a chiral molecule, set spinning by a photoionizing laser field whose polarization rotates. The electrons must pass through the spinning barrier of the molecule to escape.
