Direct Observation of Second Order Atom Tunnelling

Understand

Tunnelling of material particles through a classically impenetrable barrier constitutes one of the hallmark effects of quantum physics.

• When interactions between the particles compete with their mobility through a tunnel junction, intriguing novel dynamical behaviour can arise where particles do not tunnel independently.
• In single-electron or Bloch transistors, for example, the tunnelling of an electron or Cooper pair can be enabled or suppressed by the presence of a second charge carrier due to Coulomb blockade.
• Here we report on the first direct and time-resolved observation of correlated tunnelling of two interacting atoms through a barrier in a double well potential.