EventDetails

Speaker:
Dr. Roberto Rosati, University of Münster

Inhomogeneous electronic wave packets describe a nanometric localization of electrons (obtainable, e.g., by near field spectroscopy) [1]. Their evolution could describe travelling electrons and may thus be important in several fields, e.g., in quantum information as flying qubits [2]. The initial localization is made possible by the presence of strong interstate coherences, but may be lost during the evolution due to both coherent and incoherent phenomena, i.e., a coexistence of different group velocities and the scattering mechanisms, respectively. A proper description of the evolution of nanometric wave packets must catch the interplay between coherent and dissipative dynamics: For this purpose, we employ the (off-diagonal) density matrix formalism and account for scattering mechanisms by alternative Markov approaches [3,4], which are able to combine accurate predictions, flexibility and computational feasibility (despite the presence of the off-diagonal density-matrix elements). With these treatments, we examine different nanodevices to show different phenomena associated with an initial confinement: (i) in conventional parabolic materials, a scattering-induced loss of spatial shape due to the so-called scattering nonlocality and scattering-induced diffusion [5]; (ii) in metallic nanotubes, a shape-preserving dispersionless propagation (up to micrometers also at room temperature) [6]; finally, (iii) in 2D TMDC monolayers embedding 0D confinement potentials (obtainable, e.g., by means of strain [7] or gating [8]), a spatial control of the nontrivial spatiotemporal dynamics of the charge, which is captured in the 0D potential from the travelling wave packet due to electron-phonon scattering [9].

[1] M. Herbst, M. Glanemann, V. M. Axt and T. Kuhn, Phys. Rev. B 67, 195305 (2003)  [2] A.Bertoni, P. Bordone, R. Brunetti, C. Jacoboni and S. Reggiani, Phys. Rev. Lett. 84, 5912 (2000)  [3] R. Rosati, R. C. Iotti, F. Dolcini, and F. Rossi, Phys. Rev. B 90, 125140 (2014)  [4] R. Rosati, D. E. Reiter, and T. Kuhn, Phys. Rev. B 95, 165302 (2017)  [5] R. Rosati and F. Rossi, Phys. Rev. B 89, 205415 (2014)  [6] R. Rosati, F. Dolcini, and F. Rossi, Phys. Rev. B 92, 235423 (2015)  [7] J. Kern et al., Adv. Mater. 28, 7101 (2016)  [8] A. J. Pearce and G. Burkard, 2D Mater. 4, 025114 (2017)  [9] R. Rosati, F. Lengers, D. E. Reiter, and T. Kuhn, arXiv:1802.01409 [cond-mat.mes-hall] (2018)