Terahertz Antennas with Self-amplified Spontaneous Emission

Project Information

TERASSE

Grant agreement ID: 823878

DOI

10.3030/823878

Project closed

EC signature date 29 March 2019

Start date 1 June 2019

End date 31 March 2025

Funded under

• EXCELLENT SCIENCE - Marie Skłodowska-Curie Actions

Total cost

€ 358 800,00

EU contribution

€ 358 800,00

Coordinated by

UNIVERSITA DEGLI STUDI DI CASSINO E DEL LAZIO MERIDIONALE
Italy

Periodic Reporting for period 2 - TERASSE (Terahertz Antennas with Self-amplified Spontaneous Emission)

Reporting period: 2022-10-01 to 2025-03-31

Summary of the context and overall objectives of the project

The main goal of the TERASSE project has been to contribute to the development of Terahertz (THz) technology by addressing two overarching objectives:

OB.1 – To investigate and demonstrate novel nanomaterials and quantum mechanisms in the THz range (WP1–3).

OB.2 – To create a network of expertise in quantum and nanoelectronics, and to facilitate knowledge sharing (WP4).

Terahertz technology holds significant promise for society due to its many advantages over existing technologies. These include the potential to substantially enhance communication systems—such as advancing from 5G to 6G in mobile technology—and the ability to develop diagnostic tools with resolutions comparable to X-rays, but operating at non-ionizing frequencies.
One of the main challenges in advancing THz technology lies in the limitations of conventional materials. The THz frequency range is too high for traditional microwave technologies, which suffer from excessive losses in standard materials. At the same time, THz frequencies are too low for optical technologies, as they lead to decoherence of optical signals. However, advances in nanotechnology have introduced new materials that offer promising solutions. Additionally, the study of quantum effects has opened up possibilities for novel THz transmission devices. Both of these aspects were explored within the TERASSE project.

The first objective was addressed by investigating various types of nanostructured materials—such as graphene nanoribbons, graphene/polymer sandwiches with embedded mesoscopic structures, and atomic chains like transition metal dichalcogenides and graphene dots. These materials were fabricated and characterized for potential use in the THz range. Moreover, new physical mechanisms were studied, including the excitation of mesoscopic structures through shot noise, Rabi and Rabi-Bloch oscillations, and direct interband THz transitions. These mechanisms were modeled, and the models were used to explore the characteristics of novel THz devices, such as emitters and detectors. Experiments were also conducted to demonstrate these mechanisms and provide proof of concept for the proposed ideas.

The second objective—building a network of expertise—was achieved through the secondment of partner researchers, supported by strong training and dissemination efforts. The project involved a large number of participants (20 early-stage and 17 experienced researchers) and fostered strong collaboration between theoretical and experimental academic partners, as well as between academia and industry. Training and dissemination activities, including summer courses and dedicated conference sessions, further contributed to establishing a stable and lasting network of collaboration.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

TERASSE project has achieved all its main objectives, providing the results listed below.

In terms of new mechanisms (WP 1 and WP2), TERASSE has provided theory and models for:

- THz antennas fed via Rabi- and Rabi-Bloch oscillations;
- optical and THz transitions in carbynes and cyclocarbons;
- light absorption and confinement in 2D materials with tilted Dirac cones;
- scattering from carbon nanotubes;
- electrostatically controllable gaps in graphene bipolar electron waveguides;
- control of nano-antenna radiation spectrum and radiation pattern;
- system-level analysis of nano- and mesoscopic systems with circuit models;
- a full-wave numerical FEM analysis of nanostructures;
- the electromagnetic response of nanocomposites, also based on homogenization techniques;
- the electrothermal response of nanocomposites, with special focus on industrial graphene.

In terms of fabrication, characterization, validation and proof of concept (WP 3), TERASSE project has demonstrated:

- the fabrication of new nanomaterials such as: polymer coated single-walled carbon nanotubes films; bi-layered graphene on copper foils; multilayered graphene directly deposited on the dielectric substrates;
- the fabrication and optical verification of graphene quantum dots structured at submicron scale;
- the fabrication of quantum dots in 2D transition metal dichalcogenides;
- the observation of “blinking” mechanism with hysteresis of the optical response vs temperature;
- the characterization of industrial-grade graphene with negative temperature coefficient of the electrical resistance;

TERASSE has also provided the experimental evidence of:
- the tunability of graphene in the THz range;
- the potential use of carbyde chains films as elements of optoelectronics devices;
- the potential use of 2D hybrid perovskites as photodetectors;
- the protective coatings for 2D layered photodetectors

In terms of dissemination and exploitation, the results of the TERASSE project have been presented in:

- 49 scientific publications in peer-reviewed and indexed journals and 5 conference papers;
- many international peer-reviewed conferences (IEEE COMCAS, URSI, IEEE RTSI, TERAMETANANO, OECS, Physica, ICCT, AT-AP-RASC, NPO, PLMCN, ICNMP);
- special sections of international conferences (IEEE COMCAS 2019 and 2023, URSI General Assembly 2020, Atlantic Radio Science Meeting, URSI AT-APRASC 2022, TERAMETANANO 2024);
- seminars and poster presentations for the general audience within science-fair events and open-days;

In addition, three summer courses have been organized on “Nanomaterials” (2021), “Nano and quantum technologies” (2022), and “Nanotechnology and Sensing Technologies” (2023) open young researchers.

The results of the TERASSE project are being eploited by the partners to launch new initiatives, including proposals submitted to both international (e.g. EU Horizon MSCA, Pathfinder) and national funding calls.
Some of these proposals have already been funded, enabling the partners to continue and expand upon the work initiated through TERASSE.

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

The results of the TERASSE project represent a significant advancement over the current state of the art, as evidenced by their publication in high-quality scientific journals. The most noteworthy achievements include:

- modelling the physical mechanisms enabling THz radiation in mesoscopic systems (e.g. shot noise, Rabi and Rabi-Bloch oscillations, and interband THz transitions);
- establishment of stable and reliable procedures for fabricating novel nanostructured materials (e.g. graphene nanoribbons and graphene/polymer sandwiches);
- demonstration of unusual properties of nanomaterials through electromagnetic and electro-thermal characterization;
- validation of fabrication techniques for quantum dots based on graphene and 2D transition metal dichalcogenides;
- experimental demonstration of THz devices.

Starting from basic principles and technology concepts (Technology Readiness Level, TRL 1–2), the TERASSE project has progressed to the analytical and experimental proof of critical functions and characteristics in laboratory prototypes, achieving a final TRL of 3.

The project’s non-academic partners have gained significant benefits. By hosting a substantial number of secondments—including many involving highly experienced researchers—they have acquired valuable expertise in THz and nanomaterials technologies.

TERASSE has made a meaningful contribution to the advancement of THz technology, which holds substantial economic and societal potential. These benefits range from the development of highly efficient, compact data transmission systems to the creation of innovative diagnostic solutions.

THz spectra of Si/Al2O3 (a) substrate and (b) substrate covered with graphene,

carbyde chains films as elements of detectors and emitters

structure of a 2D-TMD HfS2 for realizing quantum dots

Nanofilm of few-layer graphene

Single layer graphene flakes coated by Zn