Hybrid Event

Event program

Friday, 5/27/2022 10:00 AM - 2:00 PM, Bellavista, Grand hotel Adriatic, Opatija 10:00 AM - 11:30 AM Invited Lectures  V. Kojić, M. Bohač, L. Pavić, K. Salamon, K. Juraić, A. Gajović (Institut Ruđer Bošković, Zagreb, Croatia) Perovskite solar cells; perovskite material stabilization by additives and influence on photovoltaic performance  Organometal lead hailde perovskite materials have shown promising properties as active layers for use in photovoltaic devices. However, the stability in ambient environment still remains a challenge due to the perovskite degradation in contact with water molecules. We have studied formamidinium lead iodide (FAPI) perovskites stabilised by polyvinylpyrrolidone (PVP). The influence of the polymer on structural stability, morphology, optical and electrical properties of perovskite thin films, as well as at the photovoltaic performances were investigated. FAPI was deposited from a single solution on electron transport layer using a one-step method. The influence of PVP on layer's morphology was explored by SEM, while XRD was used to track stability of the film in ambient environment. The optical and electrical properties was examined using photoluminescence (PL), UV-Vis and impedance spectroscopy (IS), while photovoltaic performances were studied by I-V measurements. We have demonstrated that PVP inclusion in FAPI, prevents the degradation of the film in the ambient atmosphere after ageing for 2 months. PL and UV-Vis measurements indicated less structural defects in the films with PVP, while IS indicated higher electrical conductivity. The performances of photovoltaic devices were studied and discussed in correlation with structure and stability of perovskite active layer. Giovanni Cantatore (University of Trieste, INFN Sezione di Trieste, Italy) Exploring Short Range Interactions at Micron Scale with Advanced-KWISP  11:30 AM - 2:00 PM Papers  1. A. Aiello (Max Planck Institute for the Science of Light, Erlangen, Germany) The Electric Field of a Single Photon  It is well known that the expectation value of the electric field operator in a single-photon state vanishes. However, single-shot measurements of the electric field must yield some nonzero value each time a measurement is performed. What values can be obtained, and with what probability, is perhaps less well known. In this work we introduce a simple yet rigorous field theoretic representation of single-photon states of the electromagnetic field. The formalism presented here allows us to calculate the electric field carried by a single-photon and the probability of occurrence of the values of the field in single-shot measurements. As a practical application of our theory, we calculate the electric field of a photon sent through a beam splitter. We find that the single-photon field after the beam splitter exhibits nonlocality. 2. N. Kralj, S. Saarinen, E. Langman, Y. Tsaturyan, A. Schliesser (Center for Hybrid Quantum Networks, Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark) Optically Cooling a Room-Temperature Nanomechanical Membrane Resonator Close to Its Quantum Ground State  We present a new optomechanical cavity design, comprising a fiber mirror and a mirror featuring a silicon phononic crystal structure on its backside, termed the "exoskeleton". The fiber mirror's small mass pushes the frequencies of its vibrational modes above that of the mode of interest, while the exoskeleton structure creates a bandgap in the spectrum of the latter mirror, engineered to be centered around the mode of interest. The mechanical mode of interest is a vibrational mode of a "soft-clamped" SiN membrane resonator, exhibiting quality factors well in excess of 10^8 at room temperature. Owing to its high quantum cooperativity and low mirror noise, we are able to use the optomechanical system to make an efficient and strong optical measurement of the motion of this mode and feedback-cool it to below 20 phonons at room temperature. 3. M. Peranić, M. Lončarić, A. Radman, M. Stipčević (Ruđer Bošković Institute, Zagreb, Croatia) Quantum Communication Experiments with Entangled Photon Pairs  Today, perhaps more than ever before, the security of information and communication is increasingly important. The cryptographic protocols used in classical cryptography are based on mathematical algorithms and can be breached. On the other hand, the laws of quantum physics enable quantum key distribution (QKD) and it is possible to achieve absolute security of communication based on the fundamental laws of nature. Anyone who would eavesdrop QKD-based communication must perform a measurement, which implies an impact on the system that can be detected by the sender and receiver. In this paper, we present a brief overview of QKD implementations and our experimental setup for generation of quantum key. Using this setup, we measured violation of the Bell's inequality of 114 standard deviations from the classical boundary, which confirms the non-local behavior of the entangled photon pairs. One can also use this source to create hybrid connections in combination with both optical fibers and free space. 4. D. Čakara (University of Rijeka, Centre for Micro- and Nanosciences and Technologies and Department of Biotechn, Rijeka, Croatia), P. Ritzert, D. Boyaciyan, R. von Klitzing (Technical University Darmstadt, Department of Physics, Condensed Matter Physics, Soft Matter at Int, Darmstadt, Germany) Dielectric Function of a Polymer Brush Functionalized with Gold Nanoparticles Determined from Spectroscopic Ellipsometry  Spectroscopic ellipsometry is a powerful technique for measuring the thickness and dielectric function of thin films deposited upon optically reflective surfaces. The dielec-tric function determines the material optoelectronic properties, however its ellipsometric measurement is challenging in cases when the film thickness and its exact structure in terms of phases and their optical properties, are unknown. The present paper discusses several models of film dielectric function, which may be considered for fitting the ellipsometric spectra of a poly(N-ispropylacrylamide) brush grown at silicon surface and functionalized with gold nanoparticles. 5. s. Kohneh Poushi, H. Mahmoudi, M. Hofbauer, A. Dervić, H. Zimmermann (Vienna University of Technology, Vienna, Austria) Photodetection Characterization of SPADs Fabricated in 0.35µm PIN Photodiode and High Voltage CMOS Technologies  Given the doping profiles available in different CMOS technologies, different single-photon avalanche diode (SPAD) structures could be designed. A good insight into the effect of various doping profiles on the electric field distribution within the device is crucial for optimizing the photodetection performance. In this paper, we present an experimental and simulation characterization of the photon detection probability (PDP) for two reach-through SPADs with different doping profiles, and study the effect of the electric field distribution on the PDP performance. We use a comprehensive model to evaluate the PDP up to an excess bias voltage of 13.2V. In addition, it is shown that the SPAD with a thicker high-field region, despite having the lower maximum value of the electric field, shows higher carrier avalanche triggering probabilities and, consequently, a higher PDP (67% at 13.2V excess bias and a wavelength of 642nm). The PDP at the wavelength of the absolute transmission maximum of the isolation and passivation stack at 665nm is even 84% at 13.2V excess bias. The presented results and discussions can offer a better insight to the designer to achieve higher PDP for other SPAD structures by optimizing the electric field profile using doping modifications. 6. A. Arena (University of Rijeka, INFN Sezione di Trieste, Trieste, Italy), G. Cantatore (University of Trieste, INFN Sezione di Trieste, Trieste, Italy), M. Karuza (University of Rijeka, INFN Sezione di Trieste, Rijeka, Croatia) Digital Holographic Interferometry for Particle Detector Diagnostic  In high precision scattering experiments particle tracks must often be reconstructed from a series of hits in successive detector planes. The relative distance between these planes is a critical parameter that must be monitored during operation. To address this problem we have developed a digital holographic interferometer dubbed Holographic Alignment Monitor (HAM) to be used in the MUonE project at CERN. MUonE aims at a precision measurement of the scattering angle between particles after an elastic muon-electron scattering. The HAM is designed to monitor the relative distance between position-sensitive sensor planes inside a MUonE tracking station with a resolution better than the required 10 µm. The system uses a 532 nm fiber-coupled laser source both to illuminate the object, and to provide the reference beam. A CMOS image sensor acquires the raw data, and the reconstructed holographic image of the silicon sensor being observed is computed using an algorithm containing a Fourier transform. The relative distance between silicon planes is monitored by superposing successive raw images of the same object on an initial reference one and observing the interference fringes appearing on the reconstructed holographic image. Preliminary tests have yielded a distance resolution of less than 1 µm. 7. V. Vujnović, D. Jardas, M. Karuza (University of Rijeka, Department of Physics and Centre for Micro- and Nanosciences and Technologies, Rijeka, Croatia) Optical Sensing with Dichroic Resonator  For more than a century, optical resonators (e.g., Fabry-Pérot, FP) have been used as interferometers, high-resolution spectrum analysers, fast displacement sensors in both fundamental research and in metrology. Possibility to simultaneously measure given quantity at two orthogonal polarizations led to new applications which are still being investigated. Later research showed that FP can be easily employed in modern quantum optics (atom-light strength coupling tests) and high energy physics experiments (resonant enhancement of conversion probability). We present a dichroic FP resonator that is simultaneously resonant for two wavelengths: 1064 nm and 532 nm, its properties and possible application.

Opatija is the leading seaside resort of the Eastern Adriatic and one of the most famous tourist destinations on the Mediterranean. With its aristocratic architecture and style, Opatija has been attracting artists, kings, politicians, scientists, sportsmen, as well as business people, bankers and managers for more than 170 years.

The tourist offer in Opatija includes a vast number of hotels, excellent restaurants, entertainment venues, art festivals, superb modern and classical music concerts, beaches and swimming pools – this city satisfies all wishes and demands.

Opatija, the Queen of the Adriatic, is also one of the most prominent congress cities in the Mediterranean, particularly important for its ICT conventions, one of which is MIPRO, which has been held in Opatija since 1979, and has attracted more than a thousand participants from over forty countries. These conventions promote Opatija as one of the most desirable technological, business, educational and scientific centers in South-eastern Europe and the European Union in general.

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