Acousto-optoelectronics – driving the motion of carriers in low-dimensional semiconductors

Basic data for this talk

Type of talkscientific talk
Name der VortragendenKrenner, Hubert
Date of talk12/05/2023
Talk languageEnglish

Information about the event

Name of the eventInstitutsseminar Paul-Drude-Institut für Festkörperelektronik
Event locationBerlin
Event websitehttp://www.pdi-berlin.de
Organised byPaul Drude Institut für Festkörperelektronik

Abstract

Elastic waves are an indispensable phononic technology finding applications in diverse fields ranging from the life sciences, signal processing to quantum technologies [1]. In my talk, I will show that the unique combination of surface acoustic waves (SAW) and high-resolution optical spectroscopy provides a versatile testbed to sense and manipulate the optical properties and carrier transport processes in novel nanoscale materials. I will show that the large piezoelectric fields accompanying the sound waves can drive charge carrier dynamics in nanowires and two-dimensional semiconductors giving rise to dynamic modulation of the emission intensity or inducing acousto-electric currents [2-4]. Optical spectroscopy enables the direct observation of piezo-acoustically driven dynamics on ultrafast time scales [5]. These methods provide insight on fundamental material parameters such as the mobility of electrons and holes and at the first time enable the first direct observation of the transverse angular momentum of radio frequency SAWs. [6]. Notably, this transverse angular momentum was predicted by Lord Rayleigh in 1885 manifesting itself in an elliptical motion and gyration of the piezoelectric field. Most interestingly, it also represents the acoustic manifestation of spin-momentum, an archetypical phenomenon found in different physical system for instance for electrons in topological insulators or for light in the form of surface plasmon polaritons. Our first observation opens the new field of Spin-Sonics at the intersection between nanoscale acoustics, electronics and photonics. [1] P. Delsing et al., J. Phys. D: Appl. Phys. 52, 353001 (2019). [2] L. Janker et al., Nano Lett. 19, 8701 (2019). [3] M. M. Sonner et al., Nano Lett. 19, 3336 (2019). [4] E. Preciado et al., Nat. Commun. 6, 8593 (2015). [5] M. M. Sonner et al., Phys. Rev. Appl. 16, 034010 (2021). [6] M. M. Sonner et al., Sci. Adv. 7, eabf7414 (2021).
KeywordsAkustische Oberflächenwellen, elektrischer Transport, Spin-momentum-locking

Speakers from the University of Münster

Krenner, Hubert
Professorship of experimental physics with a research focus on solid-state physics (Prof. Krenner)