Macroscopic quantum tunneling may be possible

Science : Quantum tunneling is a phenomenon in which a particle tunnels through a barrier that it could not, according to the laws of classical mechanics, surmount. It has already been demonstrated in semiconductors in which electrons tunnel through nonconducting layers of material. Mika Sillanpää of Aalto University in Finland and colleagues think that much larger objects can be made to behave similarly. They designed an experiment in which a micrometer-wide membrane made of graphene is suspended over a metal plate. With electrical voltage applied, the membrane would have two stable positions: bowed slightly in the middle, or bent enough to be in contact with the metal plate underneath. The combined electrical and mechanical forces on the membrane would create an energy barrier between the two positions. At temperatures of less than 1 millikelvin, the membrane could only move from one stable position to the other by quantum tunneling. Sillanpää says achieving the necessary low temperatures may take several years, but he and his team are moving forward with an experiment.