Abstract |
Two-dimensional conductors placed in strong magnetic fields enable ballistic
guidance of electronic trajectories. Combined with the use of electrostatic
gates for the partitioning of electric currents, the ballistic propagation of
electronic excitations has enabled the realization of electronic
interferometers, such as Fabry-Perot or Mach-Zehnder interferometers. In recent
years, the development of single electron sources has led to the emergence of
electron quantum optics, which aims at manipulating the quantum state of
individual electronic excitations propagating in a quantum conductor. While
these experiments bear many similarities to conventional quantum optics (based
on the manipulation of photons), there is a fundamental difference between the
two systems: unlike photons, electrons interact strongly with each other via the
Coulomb interaction. In highly correlated conductors, these interactions can
give rise to new elementary excitations with exotic behavior. These particles,
called anyons, have properties intermediate between fermions and bosons,
characterized by a fractional exchange phase. In my talk, I'll show how two-
particle interferometry (also known as Hanbury-Brown and Twiss interferometry)
can be used to finely characterize the elementary excitations of quantum
conductors: electrons in the regime of weak interactions and anyons in strongly
correlated conductors. |