Moty Heiblum
Resources:
The Kavli Symposia
"Interference between two indistinguishable electrons emanating from two independent sources"
Very much like the ubiquitous quantum interference of a single particle with itself, quantum interference of two independent, but indistinguishable, particles is also possible. This interference is a direct result of quantum exchange statistics, however, it is observed only in the joint probability to find the two particles in two separate detectors. I will present an observation of interference fringes between two independent and non-interacting electrons in a two-electron interferometer. In the experiment, two independent and mutually incoherent electron beams, emanating from two separated sources, were each partitioned into two trajectories. The combined four trajectories enclosed an Aharonov-Bohm magnetic flux, while the two trajectories of a single electron did not enclose flux - hence, no single electron interference was possible. Consequently, individual currents and their fluctuations, in each of the four detectors, were found to be independent of the Aharonov-Bohm B flux - as expected. However, the cross-correlation between current fluctuations in two separate detectors exhibited strong Aharonov-Bohm interference oscillations. This observation is a direct signature of quantum entanglement between the spatial degrees of freedom of two electrons ("orbital entanglement") even though they never interacted with each other.
