The project is devoted to exciton-polaritons, extremely interesting quantum particles with possible applications in various fields, such as high-precision interferometry, ultra-low power lasers and  data processing with low energy losses.

Exciton-polaritons are formed in semiconductors with a specially designed structure as a result of  extremely strong coupling of photons and excitons, which are material particles made up of an electron and a “hole”. Polaritons have a “Schroedinger’s cat” structure, i.e. the quantum state is defined by two alternatives: an alive cat, when the exciton exists, or a dead cat, when the exciton is replaced by a photon in the system.

Prof. Michał Matuszewski, photo by Michał Łepecki The InterPol project aims to create polariton lattices as a semiconductor platform for quantum simulations under laboratory conditions. The main goal is to achieve the strong quantum correlation regime, where interactions between individual polaritons will prevail over decoherence associated with photon losses, which will allow us to build simple quantum simulators. The project may play an important role in the development of accessible quantum technologies and contribute to our understanding of nanoscale non-equilibrium systems.

Prof. Michał Matuszewski, photo by Michał Łepecki The project was divided into five research tasks. The first one was to create static polariton lattices using special atomic layering methods and to engineer structures with predefined geometries. The second task was to create lattices with variable geometries, thanks to innovative light-matter coupling methods. At the third stage, samples obtained in the earlier tasks were used to create strongly correlated quantum phases. Subsequently, we will employ what is known as topological protection of quantum states to significantly extend their lifetime. Another important task is to design new theoretical models of polariton systems for a comprehensive understanding of experimental observations. The Polish team takes part in the theoretical effort, lending support to experimental studies and developing the theory of quantum phases.

Photo by Michał Łepecki Among the main achievements of the project thus far is the successful synthesis and description of two-dimensional Lieb lattices and micropillars, aimed at testing strong polariton interactions, and creating polariton lattices in an open cavity. These basic systems will allow us to implement quantum simulators. Experiments with the lattice systems allowed us to observe the emission of chiral micro laser light beams, solitons in the energy gap and flat energy bands in polariton systems. In addition, artificial photon gauge fields were created in a lattice with a honeycomb structure, which provides a very useful tool for quantum simulations. The spin-orbit effect, polarization splitting, and topological states were also observed in two-dimensional Lieb lattices. New theoretical developments included a novel method for studying the dissipative Bose-Hubbard model, which led to the discovery of an interesting bistable time crystal.

The most interesting achievements by the Polish team included proposing and reallizing a polariton lattice that allows machine learning to be implemented in quantum systems. The concept is currently being intensively developed in collaboration with experimental groups and has inspired a new NCN project carried out in a consortium with an experimental group from the University of Warsaw.

Solar energy powers life on our planet through the fundamental process of photosynthesis. Natural photosystems are made up of large membrane protein complexes, which use spatially organized systems of electron transfer cofactors and pigments to create highly efficient macromolecular nanomachines that convert solar energy into chemical energy. Converting solar power into fuel may serve as the most attractive source of clean energy as the demand for power grows in our time. In an era of global climate change, there is an urgent need to thoroughly study the molecular mechanisms of photosynthesis, especially in extreme conditions similar to those that accompanied the emergence of the first forms of life.

Photo by Michał Łepecki The structure of photosynthetic apparatus of Cyanidioschyzon merolae, an extremophilic unicellular red alga harvested from volcanic hot springs implies that this microalga constitutes an evolutionary link between cyanobacteria and higher plants. Our project studied how the photosynthetic apparatus of this thermophilic and acidophilic microalga regulates its function in extreme environmental conditions. For this purpose, we examined: (1) the pattern of dynamic changes in the structure of antenna systems (systems that capture solar power) connected to photosystems I and II (PSI and PSII) in the cells of C. merolae, as influenced by the quantity and spectral quality of available light; (2) water substrate exchange rates in the catalytic centre of PSII (an enzyme that splits water upon absorption of sunlight); (3) the role of carotenoids, i.e.  pigments, identified in PSI and PSII complexes obtained from C. merolae, which protect the photosynthetic apparatus from excess sunlight. We also looked into (4) the kinetics of the early processes of solar energy conversion, including the solar energy transfer pathways in photosystems isolated from this extremophilic microalga.

Photo by Michał Łepecki Both photosystems isolated from this fascinating extremophile were shown to be exceptionally stable under extreme pH, temperature and light conditions. The quantum efficiency of the water-splitting enzyme (PSII) also remained unchanged regardless of light conditions. Thanks to our highly interdisciplinary approach, which employed biochemical, biophysical, proteomic, and advanced microscopic imaging methods to study individual photosynthetic complexes, we were able to define the following molecular mechanisms by which the photosynthetic apparatus of C. merolae adapts to fluctuating light: (i) the accumulation of photoprotective pigments (zeaxanthin and β-carotene) in antenna complexes and photosynthetic reaction centres; (ii) dynamic changes in the structure of antennae and photochemical reaction centres in PSI and PSII complexes, on the level of both proteins and pigments, which improves the use of sunlight for cellular metabolism; and (iii) the same photosynthetic water-splitting reaction kinetics in the PSII complex of C. merolae as in its equivalent in mesophilic organisms.

We need to know these precise molecular mechanisms that regulate the high stability and photoprotection of the photosynthetic apparatus of the extremophilic unicellular alga C. merolae so as to understand the processes of efficient solar energy conversion and cellular energy homeostasis in extreme environmental conditions. The research has a high translational potential. It will facilitate the development of better strategies for manufacturing stable and efficient biomimetic devices to convert solar energy into clean fuels under extreme conditions, thus promoting a more efficient production of clean energy.

Funded under the SONATA BIS call, this project was inspired by the marked rise in drug resistance that we have now seen for more than 30 years. Drugs we have relied on until now are gradually becoming ineffective as pathogenic bacteria and fungi develop specific defence mechanisms that make them drug-resistant.

In our research, we try to understand the correlation between the coordination, thermodynamic stability, structure and mode of action of antimicrobial peptide-metal complexes.

Photo by Michał Łepecki Antimicrobial peptides (AMP) are often viewed as potential next-generation therapeutics. What offers a glimmer of hope is that even though they have been around for millions of years, barring a few exceptions, microbes still seem to have developed no resistance to these substances.

Biologically essential metal ions, such as zinc, Zn(II) and copper, Cu(II), have a dual effect on the activity of antimicrobial peptides: (1) AMPs bind metal ions, which means that microbes cannot get enough of these essential metals to survive and cause disease (metal-ion capturing, nutritional immunity) or (2) AMPs require specific metal ions to reinforce their antimicrobial action (metal ions impact AMP charge/structure). To the best of my knowledge, no prior research has looked into the various relationships between the ability of AMP to bind metal ions, their structure, mode of action and biological activity; this subject matter has become the main research domain of my team, working in tandem with our consortium partner, a team led by Dr Agnieszka Matera-Witkiewicz from the Wrocław Medical University.

We focused on the thermodynamics, structure and coordination chemistry of selected AMPs with Zn(II) and/or Cu(II) and compared these data with our results concerning the biological activity of metal-AMP complexes against selected strains of bacteria and fungi, as well as cytotoxicity against selected cell lines, which allowed us to draw important conclusions on the relationship between the structure and stability of the metal-AMP complex and its efficacy and mode of action.

Funded under SONATA BIS and, subsequently, PRELUDIUM BIS, PRELUDIUM and OPUS grants (with Joanna Wątły acting as the PI under the last of these), our research brought a number of important discoveries. For instance, we discovered that the coordination of Zn(II) to some AMPs involves a specific structural and morphological change which, in its turn, makes the entire complex effective at combating fungal pathogens. This phenomenon was observed for human amylin analogues and peptides from the shepherin group.

Our team - standing from left side: Kinga Garstka, Emilia Dzień, Silke Andra, Natalia Nogala, Dorota Dudek, Aleksandra Hecel-Czaplicka; sitting from left side: Adriana Miller, Magdalena Rowinska-Żyrek, Valentyn Dzyhovskyi, Joanna Wątły. Fot. Dominika Hull, UWr

We also got exciting results for Cu(II) and Zn(II) complexes with PvHCt, an antimicrobial peptide derived from shrimps. The coordination of Cu(II) has a very strong impact on its structure and antimicrobial properties, showing a clear and fascinating link between metal coordination, structure and function. What is intriguing is that PvHCt inhibits microbial growth only in the presence of metal ions, especially those of Cu(II), which coordinates to the central part of the peptide and its C-terminal region, thus inducing a structural change, increasing the proportion of the α-helix and initiating the formation of reactive oxygen species. Cu(II) coordination has a very clear impact on the antimicrobial activity of the complex, showing significant efficacy against E. coli, MRSA and E. faecalis, with a promising value of MIC = 16 µg/ml.

We also demonstrated the impact of a local change in the charge of AMP complexes on their biological activity and described the impact of the pre-organisation of the Zn(II) binding site on the biological properties of its complex with clavanin. Our results have been reported in more than twenty renowned publications, and our fascination with AMP complexes has not stopped there: we are now trying to go a step further and improve their proteolytic stability, i.e., make them more biologically stable. A longer half-life in the body would make AMP complexes fit for use in therapy; we are now working on a solution to the problem with the use of so-called inverso-peptides, which exhibit reversed sequences and chirality compared to the parent molecules, but an identical array of side chains, and sometimes even a similar structure. The presence of D-amino acids, which cause reversed chirality, makes them less susceptible to proteolytic degradation, thus eliminating the main drawback of peptide-based medicines, i.e., their lack of stability.

Both AMPs and retro-inverso peptides seem like a real treasure trove for scientists wishing to discover new, safe drugs with a prolonged half-life and increased potential, but this is not the only reason why we investigate them. From the point of view of chemistry, our work is also an intellectually rewarding, incredibly robust contribution to our general knowledge of the basic bioinorganic chemistry of (still unstudied) complexes of retro-inverso peptides with Zn(II) and Cu(II).

Our current repertoire is dominated by the music of the past; it reigns supreme both in concert halls and on radio stations, which love to broadcast the golden oldies. We frequently go back to the music created decades or centuries ago and accord it great importance in our culture, European and national identity, as well as a regional and generational sense of belonging. Underway since the early 19th century, this trend has been further reinforced by contemporary media. But how was the music of the past perceived several centuries ago, in the late medieval and the early modern period? Was it also somehow important then? Is it true that 15th- and 16th-century audiences preferred a largely contemporary repertoire? These questions were addressed by a research project conducted by musicologists from universities in Cambridge, Heidelberg/Zurich, Prague and Utrecht, as well as the Institute of Art of the Polish Academy of Sciences in Warsaw.

Photo by Michał Łepecki Scholars from these five research centres examined a wide variety of 13th-16th-century sources, both those that were already well known and those that were first discovered and analysed within the framework of the project, and searched them for data and music pieces that document the presence of music from the past in the medieval and the early-modern period. It turned out that such music played an important role in the identity of certain social and religious groups, e.g. the Czech Utraquists or Lutherans in Northern Germany. As early as the 13th-century, polyphonic music was being archived at the University of Paris. In the 15th and 16th centuries, alongside new works, there existed a large body of earlier pieces going back to the preceding decades but also to earlier generations and historical periods. The Warsaw team (Paweł Gancarczyk, Antonio Chemotti, Bartłomiej Gembicki) presented this phenomenon using the example of various music genres practiced in Central Europe, such as the hymns collected by the Lutheran pastor Valentin Triller (Wrocław, 1555). They also asked how this old music functions in the 21st century, both in academic discourse and among performers and listeners.

Photo by Michał Łepecki The project’s products include: four PhD dissertations, two monographs, a critical edition of music and a number of articles published, for instance, in a volume entitled Sounding the Past: Music as History and Memory (Turnhout, 2020). In accordance with the requirements of the HERA programme, the researchers put great emphasis on outreach activities, organizing seminars, workshops, concerts and exhibitions, as well as publishing popular articles and teaching young people. In this endeavour, they worked in tandem with associate partners: musical ensembles, such as Bastarda (Warsaw), La Morra (Basel), Schola Gregoriana Pragensis (Prague), Trigon (Leiden), and a new group formed as a result of the project, Anonymous III (Cambridge). Young composers from the Academy of Performing Arts in Prague composed modern pieces inspired by early music and a CD with late medieval compositions was released. The team produced several documentary films which, along with videos recorded during the concerts, are now available on their YouTube channel, “SoundMe HERA Research Project”. More information: www.soundme.eu (archived website).