Control of Elementary Excitations by Acoustic Fields

DFG-Controlling Electron-Phonon Interaction in Nanocircuits — Strong Coupling Regime

Figure: (a) Electrostatic quantum dots inside an (b) acoustic resonator defined by focusing interdigitated transducers. (c) Calculated acoustic field.

This project aims at the realization of hybrid quantum systems based on the coupling of single electrons and single phonons in the form of acoustic waves in tailored nanostructures (see figure). Our focus will be the study of the electron-phonon interaction in systems consisting of electrostatic quantum dots placed in a high-quality phonon resonator aiming at reaching the strong coupling regime. The coherent interaction between a single electron and a single phonon in such a structure will give rise to quantum hybrid states useful for quantum information applications. These states resemble those observed in circuit quantum electrodynamics, but now with a phonon replacing the microwave photon. As compared to photons, phonons have the advantage of much smaller wavelengths such that they can be matched to the size of a nanostructure to enhance the electron-phonon coupling as compared to the electron-photon coupling at the relevant energies. Phonons will also be used to couple distant qubits: they are advantageous for the remote coupling since their mean-free-path or coherence are expected to be longer than those of electronic excitations in nanostructures.

 

This project is carried out by combining the complementary expertise of Stefan Ludwig (PDI) on electron-phonon interaction in nanoelectronics and Felix von Open (FU-Berlin) on the theory of electron-phonon interactions. The role of the SAW-CREA will be the study of high-quality surface acoustic resonators embedding electrostatic quantum dots [see fig. (a)]. For that purpose, we will design and fabricate acoustic resonators with acoustic field distribution appropriate to maximize the interaction with quantum dots [see figs. (b-c)].

 

This project is a collaboration between the Paul-Drude-Institute and the Free University of Berlin supported by the Deutsche Forschungsgemeinschaft (DFG) via the DFG grant "Controlling Electron-Phonon Interaction in Nanocircuits — Strong Coupling Regime”.

Selected publications:

2 Author M. E. Msall , P. V. Santos
Title

Focusing Surface Acoustic Wave Microcavities on GaAs

Source Phys. Rev. Appl. , 13 , 014037 ( 2020 )
DOI : 10.1103/PhysRevApplied.13.014037 | Download arXiv: 1908.04980 | 3135 Cite : Bibtex RIS
M. E. Msall, and P. V. Santos

1 Author P. V. Santos , M. Msall , S. Ludwig
Title

Acoustic field for the control of electronic excitations in semiconductor nanostructures

Source IEEE , Proceedings of the 2018 Ultrasonic Symposium , 1 ( 2018 )
DOI : 10.1109/ULTSYM.2018.8579769 | 3112 Cite : Bibtex RIS
P. V. Santos, M. Msall, and S. Ludwig