Thermoelectric detector based on superconductor-ferromagnet heterostructures (SUPERTED)

Main funder

European Commission

Funder's project number: 800923

Funds granted by main funder (€)

872 150,00

Funding program

FET Future and Emerging Technologies, H2020 (2014-2020) (H2020)

Project timetable

Project start date: 01/09/2018

Project end date: 28/02/2023

Summary

This project aims to demonstrate an ultrasensitive low-temperature thermoelectric detector (TED) of electromagnetic radiation, operating at a wide range of electromagnetic fields from far infrared to the X-ray regime. The novel detection principle based on the recently discovered huge thermoelectric effects in superconductor/ferromagnet hybrid structures allows for making detectors that rival previous devices in sensitivity but are simpler to operate and suffer less from heating. This is why TEDs are easier to make into large detector arrays, which is the desired goal of today’s detector technology.
Many advances in science are directly connected to improvements in technology used in imaging the studied systems. Such improvements are the main reason behind our present understanding of the structure of the universe, or of biological processes needed in medicine. High-resolution imaging enables also commercial products ranging from passive thermal cameras used in security screening to medical imaging or even elemental analysis used to study authenticity of art. At present, the goal in ultrasensitive detector industry is to increase the number of pixels to allow for faster operation and new functionalities such as imaging combined with spectroscopy at very low signal levels. Such improvements are called for both in cosmological imaging and in studies of biological processes.
Thermoelectric effects have been known since the 1830s, and their use in detectors was suggested already in the 1940s, but owing to the fact that they usually become extremely weak at low temperatures, their use in detectors has been rare, and only concentrated above room temperature where thermal noise seriously hampers the sensitivity. In this project we build on our recently discovery of huge thermoelectric effects in hybrid structures composed of conventional superconductors and ferromagnetic insulators and propose to demonstrate the first sub-Kelvin thermoelectric detector. Based on our theoretical analysis, this detector will rival other superconducting sensors in sensitivity without the problems inherent to their operation. The existing detectors are based on measuring temperature dependent impedance and therefore require a separate bias power for their read-out. In contrast, a thermoelectric detector is self-powered by the measured radiation. This makes the manufacturing of such detectors simpler as separate bias lines are not needed and avoids the bias-induced heating limiting the low-temperature operation of such devices and lowering their resolution.
In particular, in this project we aim to demonstrate the thermoelectric detector both for X-ray and far-infrared (THz) electromagnetic radiation. To reach this goal, we will use our interdisciplinary expertise, ranging from theoretical physics and advanced nanomanufacturing and characterization to leading European researchers of superconducting detectors.