Phonon-mediated nonequilibrium interaction between nanoscale devices.
Interactions between mesoscopic devices induced by interface acoustic phonons propagating in the plane of a two-dimensional electron system (2DES) are investigated by phonon spectroscopy. In our experiments, ballistic electrons injected from a biased quantum point contact emit phonons and a portion of them are reabsorbed exciting electrons in a nearby degenerate 2DES. We perform energy spectroscopy on these excited electrons employing a tunable electrostatic barrier in an electrically separate and unbiased detector circuit. The transferred energy is found to be bounded by a maximum value corresponding to Fermi-level electrons excited and backscattered by absorbing interface phonons. Our results imply that phonon-mediated interaction plays an important role for the decoherence of solid-state-based quantum circuits.
Schinner
G J
GJ
Center for NanoScience and Fakultät für Physik, Ludwig-Maximilians-Universität, Geschwister-Scholl-Platz 1, 80539 München, Germany.
Tranitz
H P
HP
Wegscheider
W
W
Kotthaus
J P
JP
Ludwig
S
S