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Condensed Matter Physics Seminar: Inès Safi

A seminar series in condensed matter physics. 

Speaker: Inès Safi, Laboratoire de Physique des Solides, Université Paris Saclay

Title of the lecture: "A unified description of time-dependent transport in interacting quantum conductors"

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Overview

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  • Date:Starts 14 November 2023, 11:00Ends 14 November 2023, 12:00
  • Location:
    Kollektorn, MC2 building
  • Language:English

Abstract:

Driving signals can excite fundamental modes of mesoscopic systems and reveal their underlying dynamics.  The effect of a sine voltage has been described through the side-band transmission picture (SBTP); single electron’s energy is translated by the energy of n exchanged photons with the ac source. Photo-assisted current and noise are then obtained by summing over n the replica of their dc counterpart at translated dc voltages, weighted by probabilities of exchanging n photons.  Obtained for the quasiparticle current in a small superconductor-insulator-superconductor junction (SIS) within the Tien-Gordon theory,[1]  SBTP was generalized to photo-assisted supercurrent and to charging and environmental effects.[2] 

Contrary to a common belief based on absence of single electron states,3  the SBTP can be generalized to a large family of strongly correlated systems, provided minimal conditions on the underlying model are obeyed [3],[4],6.  SBTP then holds in terms of many-body correlated states, thus unifying related previous works. 1,2 It can also be generalized to dual Josephson junctions coupled strongly to an electromagnetic environment. Then the formula obeyed by the photo-assisted voltage has been recovered by F. Hekking’s group [5] and turns out to be relevant to two recent pioneering experimental works.[6]  

Using the SBTP, it can be shown that noise can be decreased by an ac voltage in a SIS junction, contrary to a theorem by L. Levitov et al.[7] This led us to revisit the characterization of on-demand single electronic excitations in non-linear conductors.  One could also infer robust methods for determination of the tunneling charge which have been implemented experimentally in the fractional quantum Hall effect.[8]

 

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[1] P. K. Tien and J. R. Gordon, Phys. Rev. 129:647  (1961)
[2] G. Falci, V. Bubbanja and G. Schön, Z. Phys. B, Cond. Matt. 85 : 451 (1991) 3 G. Platero and R. Aguado, Physics Reports 395:  1   (2004).
[3] I. Safi and E. Sukhorukov, Eur. Phys. Lett. 91 :67008 (2010).
[4] I. Safi, arXiv:1401.5950 (2014). O. Parlavecchio, C. Altimiras, J.-R. Souquet, P. Simon, I. Safi, P. Joyez, D.
Vion, P. Roche, D. Estève, and F. Portier, Phys. Rev. Lett. 114 :126801 (2015). 6 I. Safi, Phys. Rev. B 99 :045101 (2019); Phys. Rev. B 106 :205130 (2022)
[5] A. Di Marco, F. W. J. Hekking, and G. Rastelli, Phys. Rev. B 91: 184512 (2015).
[6] Shaikhaidarov, R.S., Kim, K.H., Dunstan, J.W. et al. Nature 608: 45 (2022). Crescini, N., Cailleaux, S., Guichard, W. et al. Nat. Phys. 19, 851–856 (2023).
[7] J. Keeling et al, Phys. Rev. Lett. 97 : 116403 (2006).  J. Dubois et al, Nature 502 :659–663 (2013).
[8] R. Bisognin, H. Bartolomei, M. Kumar, I. Safi, J.-M. Berroir, E. Bocquillon, B. Plaçais, A. Cavanna, U.
Gennser, Y. Jin, and G. Fève. Nat. Comm., 10 (1) :2231 (2019). M. Kapfer, P. Roulleau, I. Farrer, D. A. Ritchie, and D. C. Glattli, Science 363 : 846 (2019).