Phonon spectral density in a GaAs/AlGaAs double quantum dot

Abstract

We study phonon emission in a GaAs/AlGaAs double quantum dot by monitoring the tunneling of a single electron between the two dots. We prepare the system such that a known amount of energy is emitted in the transition process. The energy is converted into lattice vibrations, and the resulting tunneling rate depends strongly on the phonon scattering and its effective phonon spectral density. We are able to fit the measured transition rates and see imprints of interference of phonons with themselves causing oscillations in the transition rates.

Heat Driven Transport in Serial Double Quantum Dot Devices

“… 1 − 3 Because of the electronic structure 4 and controllable level detunement, DQDs are highly sensitive to their environment. Consequently, interactions of DQDs with their charge environment, photons, 5 , 6 and phonons 7 − 17 have been demonstrated and used for frequency resolved noise, photon, and phonon detection. 18 − 20 …”

“…Conceptually similar systems have in that regard been only theoretically analyzed. 38 , 59 We thus consider future experiments combining access to the phonon spectral function 17 with a dedicated study of the energy harvesting performance of our system as highly interesting.…”

“…Serial double quantum dot (DQD) devices are attractive systems for both fundamental quantum physics studies and quantum electronic-based applications with well-established charge transport properties. − Because of the electronic structure and controllable level detunement, DQDs are highly sensitive to their environment. Consequently, interactions of DQDs with their charge environment, photons, , and phonons − have been demonstrated and used for frequency resolved noise, photon, and phonon detection. − …”

“…General conclusions about the performance and ideal operating conditions of our device as an energy harvester are complex to draw due to the high degree of freedom and require knowledge of the phonon spectral function to accurately determine T ph . Conceptually similar systems have in that regard been only theoretically analyzed. , We thus consider future experiments combining access to the phonon spectral function with a dedicated study of the energy harvesting performance of our system as highly interesting.…”

Temperature-dependent broadening of coherent current peaks in InAs double quantum dots

“…For the rather low value of 𝛼 in our setup, the result agrees almost perfectly with Eqs. (11) and (12). For temperatures larger than ∼ 20 mK, we witness the 1/𝑇 behavior of the high-temperature limit.…”