Electron quantum on-off switching in mercury triatomic clusters

Electron on-off switching in mercury triatomic clusters was demonstrated from quantum beat experiments. For any excited electronic state of volcanic shape, the energy levels split due to the translational symmetry within the potential energy surface, in a symmetric and an anti-symmetric component. The amount of the energy splitting depends on the energy position from the top of the barrier of the volcanic shape. The energy splitting is estimated from quantum beat experiments. We have used a molecular fluorine laser at 157 nm to form molecular triatomic clusters in their excited electronic state. From the period of the quantum interference during de-excitation at 385, 445 and 485 nm it is estimated that the splitting of the energy levels near the barrier is /spl sim/10/sup -5/ eV. Therefore by selective excitation of the energy levels, modulation of the electron tunneling probability in volcanic barriers and hence quantum on-off switching operation is taking place.