Bloch oscillations and Wannier Stark Ladder study in Semiconductor Superlattice
type: Dataset
description: Terahertz (THz) electromagnetic field, which lies in the frequency gap between the infrared and microwave, roughly between 1 THz to 10 THz, is highly desirable for both fundamental research and application. Yet tuneable compact THz sources are still not available. On the other hand, ever since first proposed in 1970, semiconductor superlattice provides new playground for various new technique and devices of tremendous research and application interest. In this thesis, an innovative theme, relying on Bloch oscillations in a dc biased semiconductor superlattice, is explored to realize tunable compact THz source THz Bloch oscillator. For doped superlattice Bloch oscillator, we designed quantum cascade super-superlattice structure to realize Bloch oscillations whilst prohibit electrical domain formation. The designed structures were processed into various waveguide and grating devices for electroluminescence detection using Fourier transform infrared spectroscopy (FTIR). The Bloch gain of semi-insulating surface plasmon waveguide device was also measured using THz time domain spectroscopy. Even though the electroluminescence and gain at THz regime were observed, no direct evidence of Bloch emission was confirmed. For undoped superlattice, the THz emission from Bloch oscillations was observed by time domain spectroscopy. At last, the photocurrent corresponding to heavy hole and Wannier Stark Ladder (WSL) states transitions in undoped superlattice was studied. Under CW laser pumping, the photocurrent as function of the applied voltage showed multiple WSL peaks, which indicated laser induced and controllable negative differential conductance (NDC). With increasing pumping power, the nonlinear NDC regime and bistable states were investigated as well.
identifier: NNT: 2012PA112418
issued: 2026-05-13T22:05:06.328829
language: en
modified: 2026-05-13T22:05:06.328835
contact point: Organization
  fn: CCSD
keyword: bloch-oscillations
keyword: echelle-de-wannier-stark
keyword: infoeu-reposemanticsdoctoralthesis
keyword: oscillations-de-bloch
keyword: photocourant
keyword: photocurrent
keyword: physcondcm-genphysics-physicscondensed-matter-cond-matother-cond-matother
keyword: superlattice
keyword: superreseaux
keyword: terahertz
keyword: theses
keyword: wannier-stark-ladder
landing page: https://theses.hal.science/tel-00795646

Bloch oscillations and Wannier Stark Ladder study in Semiconductor Superlattice
type: Distribution
format: HTML
issued: 2026-05-13T22:05:06.378975
modified: 2026-05-13T22:05:06.291706
access URL: https://theses.hal.science/tel-00795646

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