Incoherent Effects in Hot-Electron Quantum Optics

Using dynamical quantum dot single electron pumps, high-energy (“hot”) single electrons may be injected into semiconductor systems both reliably and at a high rate. When combined with energy and time-resolved detection, electrons from these sources provide us with a new platform to probe fundamental semiconductor physics in unprecedented detail.

In this contribution, we discuss coupling single-electron sources into interferometer geometries, such as the Mach-Zehnder interferometer, where the visibility of the quantum interference acts as a sensitive probe of the properties both of the emitted electrons and their environment. We investigate the effect of the uncertainty in injection energy on the phase contributions of the path lengths and quantum point contacts.

We also present theoretical calculations of the decay rate of a hot electron subject to phonon scattering, and determine how these rates are affected by parameters such as the electron injection energy and the magnetic field. Using our calculations for both phase averaging and phonon rates, we derive strategies for minimising the effects of these processes, thus maximising the quantum-coherent properties of the electrons.