Low-noise, rapid and ultrabroadband terahertz time-domain ellipsometry enabled by spintronic terahertz emitters

Project Information

T-SPINDEX

Grant agreement ID: 101123255

DOI

10.3030/101123255

Project closed

EC signature date 23 February 2024

Start date 1 July 2024

End date 31 December 2025

Funded under

• European Research Council (ERC)

Total cost

No data

EU contribution

€ 150 000,00

Coordinated by

FREIE UNIVERSITAET BERLIN
Germany

Periodic Reporting for period 1 - T-SPINDEX (Low-noise, rapid and ultrabroadband terahertz time-domain ellipsometry enabled by spintronic terahertz emitters)

Reporting period: 2024-07-01 to 2025-12-31

Summary of the context and overall objectives of the project

Electromagnetic radiation in the terahertz (THz) range is a crucial tool for spectroscopy and material characterization, offering a contact-free, non-ionizing and non-destructive means of analyzing materials to determine their reflectivity and refractive index. It finds use in both condensed matter research and practical applications. However, current approaches to THz reflectivity measurements fall short of meeting desired criteria like being ultra-broadband, user-friendly, precise and low-noise. The ERC-funded T-SPINDEX project aims to address this gap by developing a prototype THz time-domain reflectivity spectrometer capable of swiftly determining materials’ THz refractive index. The project will leverage an innovative laser-driven coherent THz source, specifically a spintronic THz emitter.

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

We developed a spintronic emitter with polarization modulation of ~100 kHz, thereby allowing for low-noise THz field measurements.
We tested new materials in terms of spintronic THz emission.
We conducted ellipsometry measurements with a spintronic emitter as THz light source.

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)

We demonstrated a new functionality of spintronic terahertz emitters. They are emitters with a high degree of linear polarization (~1% field) and are, thus, well suited as light sources for ellipsometry.