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...

Liang Li, Wuhan High Magnetic Field Center

Jeudi 13 Novembre 2014, 14hAmphi Holweck, Esc C, 1ème etage The development of the Pulsed High Magnetic Field Facility at WHMFC Liang LiWuhan High (...) 

> Lire la suite...

Florent Tournus, Université Lyon 1

Jeudi 27 Mars 2014, 14hAmphi Holweck, Esc C, 1ème etage Dépôt de nano-aimants préformés : des propriétés intrinsèques à l’auto-organisation Florent (...) 

> Lire la suite...