Electronic states underlying peculiar Bloch oscillations in a biased semiconductor superlattice with interminiband mixing. (1st July 2022)

• Record Type: Journal Article
• Authors: Unuma, Takeya; Taga, Ikuma; Itagaki, Yuto
• Is Part Of: Applied physics express. Volume 15:Number 7(2022)
• Publication Date: 2022-07-01
• Subjects: compound semiconductors -- terahertz resonance -- electronic states -- optoelectronic properties -- superlattices; Physics -- Periodicals; Technology -- Periodicals; 621.05
• DOI: 10.35848/1882-0786/ac7776
• Languages: English
• ISSNs: 1882-0778

Abstract

Abstract: We simulate the energy eigenstates of electrons and holes, which underlie terahertz Bloch oscillations observed recently with a peculiar π / 2 phase shift, in a biased semiconductor superlattice with interminiband mixing. Electron wavefunctions are extended downstream, while some of them have a moderately first-miniband-like nature that partly resembles Wannier–Stark localization upstream. When a typical heavy-hole wavefunction is chosen, a few first-miniband-like electron wavefunctions prove to have large overlap integrals with it under relatively low bias fields. These electron wavefunctions are thus essential for the optical excitation of the Bloch oscillations, supported experimentally by the peak patterns of dc photocurrent spectra.