The ARCHERS Conference is being organized during December 6-8, 2021 on the occasion of the successful completion of the Project ARCHERS (“Advancing Young Researchers’ Human Capital in Cutting Edge Technologies in the Preservation of Cultural Heritage and the Tackling of Societal Challenges”), which has been implemented with the exclusive grant of the Stavros Niarchos Foundation (SNF). This final Conference aims to demonstrate the results achieved through the project and the contribution of the Stavros Niarchos Foundation to the Greek Research Community.

The Objective of the project was to support Early Stage Researchers and to educate and train young scientists in the cutting edge technologies, in which the Institutes of FORTH excel both on the national and the international level, thus, contributing towards reversing of brain drain or, even better, at promoting brain circulation. We proposed to accomplish these objectives via the inter-disciplinary research within the high-quality competitive research activities of the Institutes of FORTH. The areas of interest were the preservation of cultural heritage and the tackling of societal challenges, like environment, clean energy and health.

The SNF Funding allowed us to offer post-doctoral Fellowships for a total of 80.19 person-years as well as PhD Fellowships for 68.78 person-years for PhD Candidates following open calls and candidates’ evaluation. Moreover, we organized 50 Seminars within the ARCHERS Seminar Series and 4 Workshops, one for each of the areas of interest.

In this contribution we’ll exemplified the usefulness of label free electrochemical biosensors that utilizes nanolayers of glycans and peptides for improved biosensing. Molecular recognition events accompanied by conformational alternation are prone to undergo collective structural change when assembled in monolayers and can be translated to electrical signal. This phenomenon is demonstrated here for ions, small molecules and proteins biosensing. Two cases will be discussed in depth. The first will demonstrate a new method for sensing enzymes based on their protein-protein interactions and not on their biocatalytic activities. We apply this methodology and show a proof of concept for kinases, which are important cancer biomarkers that are conventionally detected based on their catalytic activity. The method we describe here is generic for developing sensitive and specific biosensors and other disease-related enzymes based on their interactions. The second case describes glycan-based sensing of enzymes through their biocatalysis. Sialylation is an enzymatic process in which sialyltransferase (ST) attaches sialic acid to glycans. Sensing enzymatic sialylation is important for evaluating of pathological events and pathogen invasion. We show that the characteristics of a biantennary N–glycan monolayer affect the biosensing of enzymatic sialylation. Desialylation of different complex sialylated N-glycans based biosensors will also be presented in light of their uses in neuraminidase (NA) viral activity and preferences studies.

Quantum optics is a research direction that led to the development of quantum technologies [1, 2], advancing investigations ranging from fundamental tests of quantum theory to quantum information processing. Central to these investigations are the optical Schrödinger cat states created by the superposition of two distinct coherent states. Despite the progress achieved so far, the development of schemes for the generation of high photon-number-shifted optical cat states with controllable quantum features is considered a challenging task and "hot" topic. Here, after a brief overview on the generation, characterization and applications of optical cat states, I will present you our recent findings concerning the development of a new method that naturally leads to the creation of high photon-number-shifted optical cat states with controllable quantum features [3-5].

1] A. Acín et al., New. J. Phys. 20, 080201  (2018)

2] I. A. Walmsley Science 348, 525 (2015)

3] M. Lewenstein et. al., Nature Phys.  17, 1104 (2021)

4] J. Rivera-Dean et. al., arXiv:2110.01032v2

5] J. Revera-Dean et al., J. Comput. Electr. (2021)

Polaritons are two-dimensional bosonic quantum admixtures of excitons and photons that form in the strong light-matter coupling in semiconductor microcavities. As composite bosons, they can undergo a BEC phase transition [1], while the order parameter of the system emerges in the form of a collective pseudo-spin of the ensemble. The inherent system non-linearities, originating from the matter component, have been effectively harnessed to demonstrate a range of spin phenomena like an optical spin-hall effect, spin switching, bistability and hysteresis [2]. At the core of these effects is an intrinsic self-induced field that arises from the spin anisotropic interactions of individual particles. Although polariton condensates are a non-Hermitian gain dissipative system, where dynamic equilibrium is attained by balancing the system gain and loss, we demonstrate that the coherence of the ensemble can be orders of magnitude longer than the individual particle lifetime [3]. This in turn enables the study of dynamic effects that are within the coherence time of the system such as a self-induced Larmor precession, that can be tuned through the strength of the non-linearity. Furthermore, a spinor condensate that performs a full precession on the Bloch sphere within its coherence time, is de-facto described as a spin-coherent state that has been proposed as the basis of a polariton spin qubit [4] in the PT-symmetric regime. We present experimental evidence for the persistent precession of the polariton pseudo-spin under the self-induced field, uncovered by partial collapse and revival of the first order correlation function (g⁽¹⁾(τ)) which underlines the coherent control capabilities of the system [5]. Building on recent advances in creating extended lattices of polariton condensates for analogue optical simulation [6], we discuss the possibilities of this optically malleable platform for the engineering of quantum correlations [7] as well as the potential emulation of two level qubit-like systems [8].

[1] J. Kasprzak et al., Nature 443, 409 (2006).

[2] L. Pickup et al., Phys. Rev. Lett. 120, 225301 (2018).

[3] A. Askitopoulos et al., arXiv:1911.08981 [cond-mat, physics:physics] (2019).

[4] T. Byrnes, K. Wen, and Y. Yamamoto, Phys. Rev. A 85, 040306 (2012).

[5] A. Askitopoulos et al., arXiv:2006.01741 [cond-mat] (2020).

[6] N. G. Berloff et al., Nature Materials 16, 1120 (2017).

[7] J. Feng et al., Phys. Rev. A 104, 013318 (2021).

[8] Y. Xue et al., Phys. Rev. Research 3, 013099 (2021).

Hydrogen technologies are a keystone in the effort to create an integrated, competitive and environmentally friendly European energy market. Fuel cells are the most attractive source of energy for many applications, as they are characterized by simplicity in construction, high efficiency and flexibility. Very important issues for the introduction of technology in the market are cost, competitive performance, but also reliable and long-term stable operation.

The seminar will present representative samples of our research activities aiming at the developing novel materials, efficient and reliable devices and integrated systems. Among others, the research concerns the development of highly active electrocatalysts, but also catalytic layers with a structure that leads to an extended and stable electrochemical interface, high catalyst utilization and reduced CRM (Pt) loadings. In this endeavor, it is essential to understand electrocatalysis and processes in the electrochemical interfaces. This understanding will lead to the rational design of materials and devices.

In addition, our research activities are extended to the level of the final power generation systems (up to 2 kW) with the design of the individual components, the construction and the study of the operation of the fuel cell stacks.