In recent years, membrane external-cavity surface-emitting lasers (MECSELs) have made rapid progress. A historical introduction will be given. The developments in this field are summarized and discussed, and an overview of the state of the art is given. Key advances, such as radical design simplification, double-side pumping and the ability to scale performance, play a major role. It also discusses the most important aspects of active region membrane design in terms of flexible pumping capabilities enabled by the absence of an integrated DBR and substrate. Specifically, optical pumping of a relative thick membrane will be discussed and the latest results from newly designed broadband structures optimized for a very wide tuning range by employing two different kinds of quantum wells, will be given. The talk will be summarized by a short glimpse into the future about extending this technology to other material systems.
About the lecturer
Dr. Hermann Kahle received his PhD in Physics at the University of Stuttgart, Germany, in 2016. The thesis was performed at the Institute for Semiconductor Optics and Functional Interfaces on the detailed investigation and optimization of red emitting semiconductor disk laser structures. He developed a novel concept – the membrane external-cavity surface-emitting laser (MECSEL) with first double-side diamond cooling implementation. After PhD graduation he moved to Tampere, Finland, where he joined the Optoelectronics Research Centre (ORC) at the Tampere University in 2017. He was granted an Academy of Finland Postdoctoral Researcher position in 2018 and was leading a research team further developing and investigating this novel category of heat spreader sandwiched membrane structures as laser gain elements with optimized cooling and broad tuning until 2022. After a short research stay in 2022 at Kassel University, Germany, he was with the Paderborn University, Institute for Photonic Quantum Systems (PhoQS) in 2023. Since April 2024 he is a Postdoctoral Research Fellow at University of New Mexico in the Department of Physics and Astronomy.
Solitons show up in many fields of physics from the monopoles and models of nucleons in strong interactions, to conducting plastics and novel memory storage devices. However, solitons are largely understood using classical physics. It is widely believed that quantum mechanics qualitatively changes some of their properties, for example causing some to quickly decay. We will describe a new method which allows for an efficient, reliable and complete treatment of solitons in quantum physics.
In the second lecture, we will describe some recent progress in constructing quantum kinks. We will describe how states, decay rates and scattering amplitudes may be found. Also we will introduce oscillons, which are thought to be the dominant degrees of freedom after violent events including some first order phase transitions and inflationary paradigms. We will describe how these new methods may be used to understand whether quantum corrections cause oscillons to decay so quickly that they are phenomenologically irrelevant.
This event is supported by the Polish National Agency for Academic Exchange, grant no. BPI/STE/2021/1/00034/U/00001.
About the speaker
Jarah Evslin got his Bachelor of Science degree in Math and Bachelor of Science degree in Physics from Caltech in 1997, he got his PhD degree in Physics from the University of California Berkeley in 2001. After that he did his postdocs in Pisa, Trieste and Brussels. Later he became an adjunct professor at the University of Pisa.
Since 2014, he is a professor at the Institute of Modern Physics, Chinese Academy of Sciences. He is the coordinator of the International Science Development Team for Fundamental Physics at the Thirty Meter Telescope. He published 112 papers in refereed journals, plus 1 book chapter and 7 proceedings. In the past, he has studied dark matter, dark energy, string theory, black holes and neutrino physics. For the past 5 years, his research has worked towards understanding why gluons and quarks are always confined in nuclei.
Solitons show up in many fields of physics from the monopoles and models of nucleons in strong interactions, to conducting plastics and novel memory storage devices. However, solitons are largely understood using classical physics. It is widely believed that quantum mechanics qualitatively changes some of their properties, for example causing some to quickly decay. We will describe a new method which allows for an efficient, reliable and complete treatment of solitons in quantum physics.
In the first lecture, classical solitons will be introduced. We will give a brief introduction to different kinds of solitons: kinks, vortices, monopoles and domain walls. We will describe them using classical field theory and note some of their applications in classical and quantum physics.
This event is supported by the Polish National Agency for Academic Exchange, grant no. BPI/STE/2021/1/00034/U/00001.
About the speaker
Jarah Evslin got his Bachelor of Science degree in Math and Bachelor of Science degree in Physics from Caltech in 1997, he got his PhD degree in Physics from the University of California Berkeley in 2001. After that he did his postdocs in Pisa, Trieste and Brussels. Later he became an adjunct professor at the University of Pisa.
Since 2014, he is a professor at the Institute of Modern Physics, Chinese Academy of Sciences. He is the coordinator of the International Science Development Team for Fundamental Physics at the Thirty Meter Telescope. He published 112 papers in refereed journals, plus 1 book chapter and 7 proceedings. In the past, he has studied dark matter, dark energy, string theory, black holes and neutrino physics. For the past 5 years, his research has worked towards understanding why gluons and quarks are always confined in nuclei.
We are excited to announce the Summer School on Organic Synthesis under Non-classical Conditions, which will be held at Institute of Organic Chemistry from September 2nd to 6th, this year!
The conference will bring together leading scientists from across Europe to share their latest research on organic synthesis under non-classical conditions.
The 4th European School of Crystal Growth will be held in Jachranka near Warsaw on 17-21.07.2024. This is a side event of the European Conference on Crystal Growth since 2015.
It is an opportunity to learn about the fundamentals and latest discoveries in various research areas related to crystal growth through extended lectures given by scientists active in their research fields. Since the Institute of High Pressure of the Polish Academy of Sciences (the main organizer) is known as the local GaN valley with almost 100 scientists actively working in the field of nitride semiconductors, part of the school will focus on the growth and characterization of gallium nitride crystals and epitaxial structures based on nitride semiconductors. We are also planning lectures on the growth of new materials, various epitaxial growth techniques, material characterization methods and computer simulation of growth processes.
These days, mankind has been starting to face many difficult issues: energy problems, environmental problems, water problems and so on. It is a common feeling that new advanced materials will play an important role in the current challenge to develop alternative and sustainable energy technologies to reduce our dependence on nuclear and fossil fuels and eliminate greenhouse gas emissions. In particular, superconducting and thermoelectric materials seem fitted to solve the energy puzzle since they can provide efficient energy transport and conversion, respectively.
This presentation will highlight the recent development of highly oriented nanostructured films of superconducting and thermoelectric materials with strongly enhanced properties for sustainable energy applications.
Superconducting bulks and single crystals are quite important for the study of the basic physical properties, however for practical applications, like direct current transportation or winding of magnets, development of superconducting wires and tapes based on thin films technology is strongly required. In the past 20 years, introduction of nanosized Artificial Pinning Centers (APCs) was widely used to strongly enhance critical current (Jc) and global pinning force (Fp) of YBa2Cu3Ox (YBCO, Tc = 92 K) and related superconducting materials in magnetic field. Furthermore, nanoengineering approach to control microstructure, distribution, concentration and dimensionality of APCs represents a powerful tool to understand the pinning mechanisms. Nanosized defects of different dimensionality, called artificial pinning centers (APCs), have been introduced in YBCO films fabricated by pulsed laser deposition (PLD). At first, by ablation of mixed BaSnO3-YBCO targets with increasing BSO content (2~9 wt%), we obtained high quality YBCO thin films incorporating BSO in form of nanorods, which are classified as one-dimensional APCs (1D-APCs). YBCO films added with 4 wt% BSO have isotropic Jc = 0.3 MA/cm2 and FpMAX = 28.3 GN/m3 (77K, 3T, B//c) [1], twice of the performance of conventional Nb3Sn superconductor at 4.2K. Secondly, we tried the incorporation of Y2O3 nanoparticles (three-dimensional APCs, 3D-APCs) inside the YBCO film, using surface-modified YBCO targets. Randomly distributed Y2O3 particles, which density was proportional to the area of sector, were incorporated in YBCO films. Consistent with the microstructure, Jc was isotropic. The 5.44 A% Y2O3 added sample presented FpMAX =14.3 GN/m3 (77K, 3T, B//c)) The single vortex dynamics model was used to account for vortex pinning in the samples [2]. Ultimate approach was combination of advantages of 1D- and 3D-APCs pinning, with coexistence of BSO nanorods and Y2O3 nanoparticles. Best result was obtained with the combination [(90 nm YBCO+BSO)/(30 nm YBCO+Y2O3)]×3 presenting FpMAX =17.6 GN/m3 (77K, 2.2T, B//c). Co-existence of random and correlated pinning in the periodically structured 1D+3D APCs-added YBCO films can be discussed on the bases of the global pinning models [3].
Thermoelectrics can convert heat into electrical energy. Efficient, small and light thermoelectric modules are fundamental to recycle waste heat from industrial plant, cars, or even domestic stoves and human body heat.
The nanostructuration of thin films and the introduction of artificial nanodefects has just recently recognized as crucial for the improvement of the performance of thermoelectric thin films, leading to depressed thermal conductivity by enhanced phonon scattering and consequent improved figure of merit ZT. Highlights of the research are: insertion of hydroquinone nanolayers in Al-doped ZnO (AZO) films prepared by atomic layer deposition (ALD): kALD (300 K) = 3.56 W/m×K [4]; addition of polymethylmethacrylate (PMMA) particles to AZO films prepared by multi-beam multi-target matrix-assisted PLD (MBMT/MAPLE-PLD): kMAPLE (300 K) = 5.9 W/m×K and ZTMAPLE (600 K) = 0.07 [5]; formation of nanopores in AZO films prepared by Mist-Chemical Vapor Deposition (Mist-CVD): kporous (300 K) = 0.60 W/m×K and ZT porous (300 K) = 0.06 [6]; dispersion of Al2O3 nanoparticulate in AZO films prepared by surface-modified target PLD: knanoAl2O3 (300 K) = 3.98 W/m×K and ZTnanoAl2O3 (600 K) = 0.0007 [7]. Overall, 1/10 ~1/100 depression of k and 3~5 times ZT enhancement with respect to the typical bulk AZO values was achieved.
In conclusion, these results clarify the crucial role of nanosized artificial defects in the improvement of performance of superconducting and thermoelectric thin films and put in evidence the promise of nanostructured films for future wide-scale energy applications.
References
[1] P. Mele K. Matsumoto, T. Horide, A. Ichinose, Y. Yoshida, M. Mukaida, S. Horii, R. Kita, Supercond. Sci. and Technol.. 21 (2008) 032002; [2] P. Mele, R. Guzman, J. Gazquez, T. Puig, X. Obradors, S. Saini, Y. Yoshida, M. Mukaida, A. Ichinose, K. Matsumoto, M. I Adam. Supercond. Sci. and Technol., 28 (2015) 024006; [3] P. Mele, M. I. Adam, T. Suzuki, Y. Yoshida, S. Awaji, A. Ichinose, S. Saini, A. K. Jha, K. Matsumoto, Sci. Adv. Mat. 6 (2017) 1042; [4] Tynell, T., Giri, A., Gaskins, J., Hopkins, P. E., Mele, P., Miyazaki, K., & Karppinen, M. J. Mater Chem. A 2 (2014) 12150; [5] A.M. Darwish, A. Muhammad, S.S. Sarkisov, P. Mele, S. Saini, J. Liu, J. Shiomi, Composites Part B: Engineering 167 (2019) 406; [6] S. Saini; P. Mele; T. Oyake; J. Shiomi; J. Niemelä; M. Karppinen; K. Miyazaki; C. Li; T. Kawaharamura; A. Ichinose; L. Molina-Luna, Thin Solid Films 685 (2019) 180; [7] P. Mele et al., in preparation
This event is supported by the Polish National Agency for Academic Exchange, grant no. BPI/STE/2021/1/00034/U/00001.
The talk is given by Dr. Sérgio Nuno Canteiro de Magalhães (IPFN, Instituto de Plasmas e Fusão Nuclear, Campus Tecnológico e Nuclear, Instituto Superior Técnico, Universidade de Lisboa, Estrada Nacional 10, 2695-066 Bobadela LRS, Portugal).
When and where?
25th June 2024, 10:30 am at the IP PAS Auditorium, duration: 45 min + question time
Recent progress in the growth techniques makes it possible to fabricate low-dimensional structures, e.g., thin films (planar multilayers), mesoscopic structures and nanostructures (lateral surface and multilayer gratings, quantum wires and dots). The opto- and micro-electronics are among the fields where the resulting novel properties of homo(hetero)-epitaxial growth of semiconductors are more significant. The optimization of the fabrication process and the physical understanding of the samples requires non-destructive structural studies of the materials. Improving the properties of the as-grown quantum materials is also fundamental from the point of view of the Nanotechnology. An example of controlled process to change the properties of materials is the ex-situ incorporation of ion species. The possibility to control dopant concentrations, depth profiling and the high purity through mass selection turn ion implantation into a silicon industry ready-to-use tool. However, the stochastic nature of the process in which energetic ions collide and penetrate the semiconductor, results in lattice damage. Although the crystal degradation is partially reversed after thermal or pressure annealing’s, vacancies and point defects introduced and rearranged after annealing create a strain field which does not disappear completely. Complementary to the direct local probing methods (atomic force microscopy, transmission electron microscopy (TEM), high angle annular dark field (HAADF) or phase analysis to determine the strain in quantum materials), the X-ray elastic scattering methods probe locally the reciprocal space, thus providing relevant information about the statistical properties of the structural parameters averaged over a large volume of a sample. X-ray diffraction (XRD) and reflectivity (XRR) in the specular and non-specular geometries are relevant techniques for these structural studies of both crystalline and amorphous systems. They are highly sensitive to the distribution of the lattice parameters (diffraction) and refractive index (reflectivity). This presentation explores the synergy between ion beam implantation and X-ray scattering techniques to advance the understanding of implanted crystalline materials. Several examples of implanted single and polycrystalline crystals will be presented following by an overview of the required theoretical principles underlying both techniques. To predict the decrease of the crystalline induced by the ion implantation, a new approach to the interpretation of the diffraction data of implanted crystals will be presented. The novel methodology considers the effects of the variations of the atom’s positions in the lattice instead of employing the static Debye-Waller, strictly related to thermal vibrations. The new method, supported by preliminary molecular dynamics simulations, is tentatively applied to chromium implanted Ga2O3 and carbon implanted 4H-SiC bulk-crystals and to argon implanted GaN thick layers grown by MOCVD on sapphire-c substrates. Finally, a brief description of the MROX software, acronym for Multiple Reflection Optimization package for X-ray scattering used to simulate the XRD data, is highlighted.
This event is supported by the Polish National Agency for Academic Exchange, grant no. BPI/STE/2021/1/00034/U/00001.
About the speaker
Sérgio Nuno Canteiro de Magalhães (ORCID number: 0000-0002-5858-549X; Web of Science ResearcherID: A-6709-2018) is a DL57 researcher under the 16/IPFN contract at Instituto Superior Técnico in Lisbon, Portugal. This contract was awarded for the development of models aimed at studying the effects of ion-implanted nano-materials using X-rays and ion beams.
Sérgio Magalhães’s journey into the realm of crystal growth began with the exploration of recent advancements in techniques, which have revolutionized the creation of low-dimensional structures. These structures, encompassing thin films, mesoscopic forms, and nanostructures, hold immense significance for Condensed Matter Physics, particularly in opto- and micro-electronics. Their uniqueness stems from the epitaxial growth of semiconductors, facilitated by cutting-edge crystal growth methods.
Sérgio Magalhães’s fascination with enhancing the attributes of these materials led to delve into the realm of Nuclear Sciences. Here, Sérgio Magalhães discovered the pivotal role of controlled processes in modifying materials, particularly through ex-situ incorporation of ion species. This method allows for precise manipulation of dopant concentrations, depth-profiling, and ensuring high purity through mass selection, thereby positioning ion implantation as a key tool for integration into the silicon industry. However, the journey is not without its challenges. On the on hand, the stochastic nature of ion implantation brings forth lattice damage as energetic ions interact and penetrate the semiconductor lattice. While thermal or pressure annealing offers partial relief, the introduction of vacancies and point defects during this process leaves behind residual strain fields that persist beyond annealing. On the other hand, the advanced measurements acquired from X-ray scattering and ion beam techniques demand equally sophisticated computer software tools to simulate their data. In response to this need, the MROX (Multiple Reflection Optimization) package for X-ray diffraction/reflection software has been recently developed. It should be emphasized that program made by Sérgio Magalhães allows to simulate XRD data of advanced semiconductor structure systems (superlattices, nanowires, quantum-dots, thin layers, ion implanted structures) what is impossible in commercial available XRD software. Already, MROX program has been credited in 16 research manuscripts published in reputable international peer-reviewed journals. Driven by the quest to unravel these complexities and enhance material properties, Sérgio Magalhães embarked on a mission to conduct non-destructive structural investigations. Leveraging X-ray and ion beam techniques, Sérgio Magalhães’s goals are to gain deeper insights into the mechanisms of damage accumulation in crystals. The success has been bolstered by over 60 research publications, facilitated by numerous international collaborations, including partnerships with esteemed institutions such as the Institute of Physics at the Polish Academy of Sciences.
In the first part, the talk will focus on capillary rise mechanisms in heterogeneous porous material with different capillary sizes. Both theoretical and experimental work are performed to investigate the time evolution and the exchange at the interface of different porous media. It contains the homogeneous capillary (without layer exchange), which is presented to distinguish the different characteristic times and the liquid capillary rise regimes. Considering gravity effect, shear stress and inertia, three regimes are distinguished theoretically and experimentally based on these two dimensionless parameters (Bo and Ga). Theoretical analysis and simulation results show the capillary rise in tendency and the appearance of oscillatory phenomenon. The heterogeneous porous media are also investigated. A multilayer domain is adopted to model the multiple distribution in capillary sizes. The interaction between these layers (different equivalent capillary sizes) demonstrate how the cooperation appears in nature so as to fit with the optimal situation of fast filling the porous media or the equivalent in drying. Experimental results on both homogeneous and heterogenous cases have a favorable effect on the imbibition enhancement. In the second part, the talk will complete with the local and global evaporation in such complex porous media.
This event is supported by the Polish National Agency for Academic Exchange, grant no. BPI/STE/2021/1/00034/U/00001.
About the speaker
Prof. Dr. Ing. Rachid BENNACER: is an Engineer in Mechanical field (1989), and he got his PhD thesis at Pierre et Marie Curie University (Paris 6) in 1993. He worked as lecturer in the University Paris XI (1993/94), became an associate professor at Cergy Pontoise University in 1994 and full Professor in 2008. He moved as senior Professor to the prestigious school Ecole Normale Superieure (Paris-Saclay) since 2010. He becomes in 2017 an Exceptional National Class Professor. He is also adjunced professor at Tianjin Uni. Of comm. (China) and UMB Univ. He assumed several responsibilities, director of the LEEVAM research team (2003-2007), Licence degrees & Aggregation title (2008-2011), Master research degree (2011 2013), Transfer and Environmental Research Unit (CNRS LMT-Lab) (since July 2012), dean of Civil/Environmental department (Oct. 2012/Sep. 2016) and 2019/2023 Coordinate International Affairs Related to Ph.D Univ. Paris-Saclay; President of ENS Paris-Saclay Special Executive committee and vice Dean of the ISI Graduate school. His present research activity is within the LMPS laboratory. His Research field covers wide spectrum and several domains. It covers the building material for energy applications or on durability aspect, renewable and energy system. The expertise covers the direct numerical simulation including CFD coupling on multi-scales. The previous approach is consolidated by analytical or reduction approach in order to identify the instabilities and global behavior bifurcation and similarity controlling parameters in multiphysics situations. He published around 10 book chapters and more than 300 referenced international journals (Rank A).
The STER workshop runs over five days, with each day dedicated to a specific topic. The school is a workshop aimed at PhD students and young researchers in physical chemistry to familiarise themselves with the latest topics in physical chemistry.
World class lecturers
A tutorial lecture will be given by an internationally renowned speaker followed by lectures by students and local experts.
Register now – limited number of places.
Don’t miss this opportunity to learn from our guests and get feedback on your research. Young researchers can apply for talks or poster presentations.
The Warsaw Doctoral School in Natural and Biomedical Sciences and the Institute of High Pressure Physics PAS cordially invites you to a SPOTLIGHT TALK.
The talk is given by Dr. Cecilia Mortalo (Consiglio Nazionale delle Ricerche – Instituto di Chemica della Materia Condensata e di Technologie per l’Energia (CNR-ICMATE), Corso Stati Uniti 4, 35127 Padova, Italy).
When and where?
19th June 2024 2024, 12:30 pm at the IHPP PAS New Technologies Building, Al. Prymasa Tysiąclecia 98 Duration: 60 min + more
Hydrogen separation and purification technology is a key element in the use of H2 as an energy carrier and in other important technological applications. Dense ceramic materials based on mixed ionic and electronic conductors (MIEC) are currently attracting growing interest for their potential application in H2 separation membranes or in catalytic membrane reactors at T > 600°C. Indeed, these membranes allow a selective non-galvanic separation by incorporating H2 in their crystal structure as charged protonic defects and electrons/holes that are transported to the opposite side of the membrane under an H2 partial pressure gradient, i.e. without any external energy. When used as membrane reactors, they also combine separation and reaction in a single unit, increasing efficiency.
In this context, ceramic-ceramic (cer-cer) composites have gained interest in the last 5 years due to their improved hydrogen permeability compared to single phase materials. Among these, dual-phase membranes based on ceria zirconate perovskites and doped ceria oxides have demonstrated remarkable performance as dense H2-separation membranes, with H2 flux values among the highest reported in the literature for this type of system.
The seminar will provide a comprehensive overview of the use of proton conducting ceramic membranes for hydrogen separation, with particular emphasis on dual-phase ceramic membranes based on BaCe0.65Zr0.20Y0.15O3-δ (BCZ20Y15) perowskite and doped ceria (Ce0.85M0.15O2-δ M = Y or Gd, YDC15 or GDC15) composites. The preparation methods, hydrogen permeability and chemical stability issues are also discussed.
