Electron-phonon correlations in driven quantum dots

The complete knowledge of the statistics and, in concrete, the
properties of the fluctuations of the number of particles emitted from
a quantum system has been a topic of intense studies in quantum optics
and, in more recent years, in quantum transport. In particular, purely
quantum features like an anti-bunching of photons emitted from a closed
two-level atom under a resonant field (Resonance Fluorescence), or a
bunching of electrons tunneling through interacting two-levels quantum
dots have been reported.

We propose a solid state analogue to Resonance Fluorescence systems in
a two-level quantum dot irradiated by a time-dependent monochromatic ac
field where the statistics of the spontaneously emitted phonons and the
transmitted electrons can be studied. Recent experiments have achieved
to measure high order moments for the non-driven electronic case in
similar systems, but the phonon case is still unchallenged. We develope
a method that allows us to extract simultaneously the full counting
statistics of the electronic tunneling and relaxation (by phononic
emission) events as well as their correlation. We find that the quantum
noise of both the transmitted electrons and the emitted phonons can be
controlled and tuned back and forth between sub and super-Poissonian
values by the manipulation of the external parameters: the driving
field intensity and the bias voltage. Further, this method allows us to
obtain the electron-phonon correlations and study how they can be
affected by the driving field.

R. Sánchez, G. Platero and T. Brandes, Phys. Rev. Lett. 98, 146805 (2007).
R. Sánchez, G. Platero and T. Brandes, Phys. Rev. B 78, 125308 (2008).