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Amplification of coherent sub-THz acoustic phonons in superlattices. Fashioning and Pumping up the sound and the SASER issue LACUS Seminar


Event details

Date and time 16.05.2019 16:3017:30  
Place and room
Speaker Prof. Christos Flytzanis
Laboratoire de Physique, ENS
Université PSL, France
Category Conferences - Seminars

We present and demonstrate(1) a novel concept and scheme of acoustic phonon amplification at sub-THz frequency  and a few nanometers wavelength range based on the photodriven acoustoelectric(AE) effect(2) with 100fs light pulses in an electrically biased semiconductor superlattice(SL) GaAs/AlGaAs; the amplification is due to stimulated Cerenkov folded zone ac-phonon(3) emission by electrons undergoing intra-miniband transport. The process is accounted for with a detailed theoretical model and extensions are discussed.
With appropriate phononic microcavity configuration it can allow the realization of the SASER (Sound Amplification by Stimulated Emission of Radiation) operation(4) the analogue of the Laser with sound. In the present configuration it is the analogue of the quantum cascade laser with sound in the sub-THz frequency and a few nm wavelength range. Such a coherent  phonon source allows for investigations with very high spatial resolution, almost comparable to that of an electron microscope, e.g. in microelectronic devices or in microbiology.
1. K. Shinokita, Kl. Reimann, M. Woerner, Th. Elsaesser, R. Hey  & Chr. Flytzanis,                                                        
    Phys. Rev. Letts 116, 075504 (2016).
2. For a review, see N. I. Meyer and  M. H. Jørgensen, in Festkörperprobleme X,
    edited by O. Madelung (Vieweg, Braunschweig, 1970). pp. 21–124.
3. M. A. Stroscio and M. Dutta, Phonons in Nanostructures, Cambridge Uni Press 2001.
4. J.C. Jackson, Plasma Phys. Controlled Fusion 28, 669(1986) ; I.V Volkov,S.T. Zavtrak, I.S. Kuten,
    Phys. Rev.  E 56, 1097 (1997); R.P. Beardsley,  A.V. Akimov,  M. Henini & A.J Kent , Phys. Rev. Letts  
    104, 085501 (2010)

Practical information

  • General public
  • Free
  • This event is internal



  • Annick Gaudin Delmonaco