Stefan Ludwig, Fakultät für Physik, Ludwig-Maximilians-Universität, Munich

Jeudi 20 Fevrier 2014, 14h
Amphi Holweck, Esc C, 1ème etage

Electron-Phonon Interaction in Nanostructures :
Detector Backaction, Phonon Interference and Single Phonon Detection

Stefan Ludwig
Fakultät für Physik, Ludwig-Maximilians-Universität

Electron-phonon interaction can strongly influence the dynamics of mesoscopic quantum circuits ; in nanostructures it can be further enhanced by size effects. A prominent example is detector backaction where phonons emitted from a non-equilibrium detector destroy the coherence of solid-state qubits. Taking a more optimistic perspective, it seems thinkable to actually use phonons for information processing in electron-phonon hybrid-systems.

In this talk I will present few experiments performed in the two-dimensional electron system of a GaAs/AlGaAs heterostructure which demonstrate the significance and potential of electron-phonon interaction for future technologies in semiconductor based nanoelectronics. After considering the electron-phonon interaction of a single hot electron in two dimensions [1] we will discuss phonon-mediated backaction from a quantum-point-contact charge detector onto a double quantum dot qubit [2,3]. We will explore quantum interference in phonon absorption in the double quantum dot and discuss its implications for detector backaction [3]. Finally, I will explain the possibility to use double quantum dots as single phonon detectors or emitters, the starting point of phononic information processing ?

Only if time permits I will briefly introduce a recent experiment which probes the electron-phonon interaction in a double quantum dot using Landau-Zener interferometry [4].

references :

[1] Phonon-mediated non-equilibrium interaction between nanoscale devices ;
G.J. Schinner et al. : Phys. Rev. Lett. 102, 186801 (2009).

[2] Phonon-mediated vs. Coulombic Back-Action in Quantum Dot circuits ;
D. Harbusch et al. : Phys. Rev. Lett. 104, 196801 (2010).

[3] Quantum interference and phonon-mediated back-action in lateral quantum-dot circuits ; G. Granger et al. : Nature Phys. 8, 522–527 (2012).

[4] Characterization of Qubit Dephasing by Landau-Zener Interferometry ;
F. Forster et al. : arXiv:1309.5907.

Haut de page

À lire aussi...

Sergio Vlaic, LPEM-UMR8213/ESPCI Paris Tech Paris

Jeudi 12 Février 2015 14hAmphi Holweck, Esc C, 1ème etage Atomic-scale engineering of magnetic anisotropy of nanostructures through interfaces (...) 

> Lire la suite...

Klaus Ensslin, ETH Zurich

Jeudi 20 Mars 2014, 14hAmphi Holweck, Esc C, 1ème etage Imaging of integer and fractional quantum Hall edge states Klaus Ensslin ETH Zurich (...) 

> Lire la suite...