Combined Structural and Voltage Control of Giant Nonlinearities in Semiconductor Superlattices.

Mauro Fernandes Pereira,Apostolos Apostolakis

doi:10.3390/nano11051287

Abstract

Recent studies have predicted a strong increase in high harmonic emission in unbiased semiconductor superlattices due to asymmetric current flow. In parallel, an external static bias has led to orders of magnitude control of high harmonics. Here, we study how this control can affect the operation of superlattice multipliers in a range of input frequencies and powers delivered by commercially available GHz sources. We show that the strongly nonlinear behavior can lead to a very complex scenario. Furthermore, it is natural to ask what happens when we combine both asymmetry and voltage control effects. This question is answered by the simulations presented in this study. The efficiency of high-order even harmonics is increased by the combined effects. Furthermore, the development of ‘petals’ in high-order emission is shown to be more easily achieved, opening the possibility to very interesting fundamental physics studies and more efficient devices for the GHz–THz range.

Highlights

Nanomaterials 2021, 11, 1287. https://Semiconductor superlattices (SSLs) are nanomaterials constructed atom-by-atom by means of epitaxial growth techniques, and they make in many ways, the ideal system to study quantum transport and optics controlling both structural parameters and applied fields [1,2,3]
The experimental detection of coherent Bloch oscillations and Stark ladders [4] was the first step for the development of SSL multipliers (SSLMs) as sources and heterodyne detectors, generating higher order harmonics well within the far-infrared
quantum cascade lasers (QCLs) emission stems from intersubband optical transitions, in contrast with the mechanisms underlying high-order harmonic generation (HHG) in SSLMs, which we briefly summarize

Summary

Introduction

Nanomaterials 2021, 11, 1287. https://Semiconductor superlattices (SSLs) are nanomaterials constructed atom-by-atom by means of epitaxial growth techniques, and they make in many ways, the ideal system to study quantum transport and optics controlling both structural parameters and applied fields [1,2,3]. These SLED structures can in principle be synchronized with the potential to become input sources with a much higher output power [8], which can be combined with. SSLMs to create hand-held devices for a large number of state of the art gigahertz–terahertz spectroscopic techniques. This scenario can become even more interesting with quantum dot and graphene superlattices [9,10,11,12,13]. When an SSLM is biased, an input oscillating field can modulate the Bloch oscillations giving rise to HHG [29,30,31,32].

Methods

Results

Conclusion