Vienna physicists create tap-proof waves

Vienna physicists create tap-proof waves: Quantum physicists at the Vienna University of Technology are proposing a new method to let waves travel on simple, straight trajectories. Applying this idea to acoustic waves, it would be possible to communicate with a person at the other side of a room without anyone else being able to hear anything...

The shape and texture of the walls or play an important role, just like the roughness of the floor. “In the theoretical model, the behavior of the wave is described by a scattering matrix – a mathematical object that characterizes wave transport”, Florian Libisch explains. In the experiment, this scattering matrix has to be measured first – for instance by transmitting several reference signals prior to the actual message. The new wave guiding procedure then determines how the wave has to be tuned to keep it on the predetermined path.