FisMat2017 - Submission - View

Abstract's title: Quantum propagation of a correlated electron-hole pair in semiconductor heterostructures
Submitting author: Federico Grasselli
Affiliation: Scuola Internazionale Superiore di Studi Avanzati (SISSA)
Affiliation Address: Via Bonomea n.265, Trieste, Italy
Country: Italy
Oral presentation/Poster (Author's request): Oral presentation
Other authors and affiliations: Andrea Bertoni (S3 Consiglio Nazionale delle Ricerche Istituto Nanoscienze), Guido Goldoni (Dipartimento di Scienze Fisiche, Informatiche e Matematiche, Università degli Studi di Modena e Reggio Emilia and S3 Consiglio Nazionale delle Ricerche Istituto Nanoscienze)
Abstract

We report on the exact space-and-time-dependent dynamics of a correlated electron-hole pair in non-perturbative in-plane external fields in semiconductor layered heterostructures.

Exact time-dependent Schrödinger propagation for tens of picoseconds of this two-body system has been performed in a wide range of scattering potentials, including ramps, wells, barriers, quantum point contacts, anti-dots, which model gate-generated potentials in typical semiconductor nanostructures. Since gates produce an electrostatic field of opposite sign for the two particles, the scattering substantially shakes internal degrees of freedom, and generally entangles the centre-of-mass (c.m.) and relative motions. This induces complex transient phenomena, and leads to strong renormalization of, e.g., transmission resonant energies and tunneling probabilities at asymptotic times, as well as diffraction patterns which are not expected in the commonly adopted, simplified picture where the electron-hole pair is viewed as a single-particle.

Common mean-field approaches are proven to fail in reproducing this phenomenology. We show that internal virtual transition are the fundamental missing ingredient, and can be restored by a properly-designed local self-energy potential acting on the the c.m.

This leads to a very good agreement with exact calculations at the very reduced numerical cost of mean-field calculations.


References:


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FG, Andrea Bertoni, and Guido Goldoni. "Space- and time-dependent quantum dynamics of spatially indirect excitons in semiconductor heterostructures." J. Chem. Phys. 142(3):034701, 2015.

FG, Andrea Bertoni, and Guido Goldoni. "Exact two-body quantum dynamics of an electron-hole pair in semiconductor coupled quantum wells: A time-dependent approach." Phys. Rev. B, 93(19):195310, 2016.

FG, Andrea Bertoni, and Guido Goldoni. "Time-dependent scattering of a composite particle: A local self-energy approach for internal excitations." Physical Review B 94(12):125418, 2016.