Periodic Reporting for period 1 - CHIROTRONICS (Controlling chirality in atomically thin quantum electronic materials)
Periodo di rendicontazione: 2022-11-01 al 2025-04-30
The recent appearance of atomically thin quantum electronic materials with handedness has opened new avenues in this interdisciplinary field. A wide variety of exotic and gigantic chiral phenomena are predicted to occur in these novel quantum systems. Moreover, these effects are expected to be actively controlled by local fields, and therefore useful for applications. However, such responses have yet to be detected, are puzzling and bring in new conundrums that demand investigation.
CHIROTRONICS has two main objectives. Firstly, by combining expertise from different disciplines such as materials science and metrology, the study aims to experimentally observe the striking chiral responses predicted to occur in chiral, atomically thin quantum electronic materials. Intriguingly, the exploration of these interdisciplinary effects will also contribute to shed light on central questions existing in many areas of knowledge where chirality is involved. Secondly, the project will show how the chiral signals arising in these quantum materials can be actively controlled and enhanced by local fields, as well as harnessed to engineer a range of basic enantioselective and non-reciprocal optical and electronic devices. Such disruptive systems have the potential to be used in many emerging applications including biochermical sensing or quantum communications.
During the first period of the project, we have developed a technique to fabricate high-quality samples made from stacked atomically-thin materials with large lateral dimensions, up to hundreds of micrometers. Moreover, we have build-up a custom-made, multi-frequency setup in order to undertake the electrical, optical and optoelectronic characterization of the fabricated atomically-thin quantum electronic materials at different wavelengths, temperatures and (eventually) in the presence of an external magnetic field.
Thanks to the aforementioned samples and measuring setup, we have already observed some of the chiro-optical and chiro-optoelectronic effects expected to occur in these quantum systems, as well as the modulation of these signals when varying the doping level in the materials. Furthermore, we have noticed the fact that absorption phenomena taking place in chiral materials may impact (reduce) the strength of chiro-optical responses, which comprises a first step towards the selection of suitable experimental conditions (frequency ranges and doping levels) where chiral effects are maximal.
Finally, as an unexpected but relevant result, we have observed intriguing and robust resonances in the optoelectronic response of these atomically-thin materials in the far infrared (terahertz frequencies). After undertaking a detailed investigation, we have ruled out the influence of chirality in the observed phenomena and ascribed these effects to the excitation and interference of plasma waves in the systems.
These works have been published in high impact factor journals such as NanoLetters or Advanced Functional Materials, and presented in several conferences such as IEEE NMDC, NANOSEA, CMD31-EPS, among others.
So far, CHIROTRONICS has produced techniques able to fabricate high-quality samples of atomically-thin layered materials with large sizes (lateral dimensions up to hundreds of micrometers). Samples of these qualities and sizes are not only needed for this Action (they have already allowed us to observe large and gate-tuneable chiro-optical phenomena), but also to study many other novel and intriguing optical effects expected to occur in these quantum systems at low frequencies. The details of the developed fabrication technique will be unveiled in an upcoming publication, so the method can be tested eventually used in other laboratories working with atomically-thin layered materials.
Furthermore, CHIROTRONICS has unveiled the resonant detection of THz radiation for the first time at room temperature. This phenomenon enables the realization of frequency-selective and frequency-tuneable THz photodevices, systems with a vast potential to be used in a myriad of applications including upcoming 6G communications, noninvasive imaging or biosensing.
Finally, while exploring the impact of absorption phenomena in chiro-optical response of layered materials, CHIROTRONICS has revealed the possibility to design efficient photothermal devices with a chiral properties. Such devices have the potential to be used in applications such as solar energy conversion, photothermal signal generation in radiometry and nanomedicine or laser-induced explosion.