Nanostructures and nanoelectromechanical devices for precise control of topological defects/matter in superfluid helium

Informations projet

N2PCON

N° de convention de subvention: 101061892

DOI

10.3030/101061892

Projet clôturé

Date de signature de la CE 7 Juillet 2022

Date de début 1 Août 2022

Date de fin 31 Août 2024

Financé au titre de

• Marie Skłodowska-Curie Actions (MSCA)

Coût total

Aucune donnée

Contribution de l’UE

€ 199 694,40

Coordonné par

AALTO KORKEAKOULUSAATIO SR
Finland

Periodic Reporting for period 1 - N2PCON (Nanostructures and nanoelectromechanical devices for precise control of topological defects/matter in superfluid helium)

Période du rapport: 2022-08-01 au 2024-08-31

Résumé du contexte et des objectifs généraux du projet

This project aims developing new nanodevice tools for probing and manipulating phenomena in quantum fluids. To be specific, in the first part of this work, a NEMS-based oscillator has been developed. This nano oscillator should be able to precisely probe quantum vortices in liquid He-3. In the second part of this work, a nanopillar structure has been developed and it should be able to confine quantum vortices and half quantum vortices.

By accomplishing these goals, new tools would be introduced to the research community of quantum fluids, largely accelerating the development of this field. The nanodevices developed in this project could also be exploited in other research communities like medical science, microelectronics, etc.

Travail effectué depuis le début du projet jusqu’à la fin de la période considérée dans le rapport et principaux résultats atteints jusqu’à présent

1. By introducing a new low-stress SiNx sacrificial layer technology, a sensitive NEMS oscillator was developed. The resonating first-order resonance frequency is below 100 kHz, which fits the measurement scheme. Different designs of oscillators were developed, of which the lightest one is ~2 pg and the highest Q-factor is 8000. These figure-of-merits ensure the capability of precisely probing quantum vortices. Moreover, multiple oscillators on the sample chip were also developed, which allows more possibility of manipulating quantum vortices and probing more fascinating phenomena.

2. By developing a new electron beam lithography patterning technique, I successfully accomplished patterning of an array of circles (11 nm-13 nm) which can be used for the creation of the high-aspect ratio nanostrands. The resulted nanostrands are with 11 nm-13 nm diameter and 200 nm of height, which will satisfy the measurement scheme in liquid He-3.

3. Variation of the nanostrand structures (random structures without an array) were also developed and collaborated with other researchers for more application scenarios. A robust superhydrophobic surface was demonstrated and an optical diffuser application was also demonstrated. The optical diffuser shows light concentration capability which can be used to increase the performance of solar cells.

Progrès au-delà de l’état des connaissances et impact potentiel prévu (y compris l’impact socio-économique et les conséquences sociétales plus larges du projet jusqu’à présent)

In this project, nano-oscillator and nanostrands were developed and key figure-of-merits were analyzed to ensure they can work in He-3. Moreover, regarding the nanostrands, applications towards photonic and superhydrophobic surface were explored with collaborators.

1. In the future, both the oscillator and nanostrands can be deeply integrated with silicon MEMS devices (microgear systems, etc.) to allow more degrees of freedom. In this scenario, more complex measurement in liquid He-3 can be set up.

2. Regarding the oscillator, medical applications like molecular detection can be developed.