Faculty of Physics University of Warsaw > Events > Seminars > "Modeling of Complex Systems" Seminar

"Modeling of Complex Systems" Seminar

2018/2019 | 2019/2020 | 2020/2021 | 2021/2022 | 2022/2023 | 2023/2024 | 2024/2025

room 1.03, Pasteura 5 at 15:15

dr Magdalena Popielska (IFT UW)

Electronic and optical properties of van der Waals layered magnets

Join Zoom Meetinghttps://zoom.us/j/93189806128?pwd=L1JGYkF4RXBmR3QyRlJYTXBKTFVPZz09Meeting ID: 931 8980 6128Passcode: Sb5RxJ

Atomically thin, magnetic materials have recently gained a lot of attention in the field of two-dimensional (2D) materials. Single magnetic layers with critical temperature above room-temperature are extremely attractive for fundamental studies and could potentially be the basis for a new class of information storage. However, probing the magnetic order of the 2D systems by conventional magnetic experimental setups is very challenging. On the other hand, it is well known that even in the single layer limit, semiconducting two-dimensional materials strongly absorb light. Therefore, optical spectroscopy is a good methodfor their characterization. In order to shed light on the intriguing phenomena of 2D magnetism, I will present theoretical investigations in the framework of the density functional theory (DFT) of the structural, electronic and optical properties of the layered materials from the large family of transition metal phosphorus trisulfides (MPS3). In particular, I will focus on excitonic properties of MnPS3 and I will compare the results for the bulk and monolayer system. The magnetic properties of alloy system Ni0.75Cr0.25PS3 and bilayer heterostructure NiPS3/FePS3 will be discussed. Finally, the impact of the intralayer and interlayer magnetism on the electronic structure for particular systems will be highlighted.

join us at 15:15

dr Mateusz Iskrzyński (System Research Institute, PAS)

Structure and vulnerability of weighted empirical food webs

Join Zoom Meeting
https://zoom.us/j/99860147224?pwd=YXNTTVRYNGpwaG5tNW03eW5YYWdJdz09
Meeting ID: 998 6014 7224
Passcode: 02GjXT

Seminar on ZOOM platform:
Join Zoom Meeting
https://zoom.us/j/99860147224?pwd=YXNTTVRYNGpwaG5tNW03eW5YYWdJdz09
Meeting ID: 998 6014 7224
Passcode: 02GjXT
Abstract: Species extinctions are compromising ecosystem functioning and services around the globe. The effects of species loss propagate over food webs (trophic networks). Food webs are directed graphs that represent feeding relationships, encoding matter flows as links between groups of species in an ecosystem. Previous food web research has been limited by reliance on purely theoretical models, few food webs, and only unweighted networks.In this seminar I will present our research on food web structure and vulnerability based on the world's largest database of 245 weighted empirical food webs. Assuming donor-controlled flow dynamics, we simulate the effects of removing a single node. We fit statistical models explaining the observed values of vulnerability indicators through a range of structural properties. I will also briefly look into the mass cycling in food webs and compare it with economic networks.

room 1.03, Pasteura 5 at 15:15

dr Krzysztof Jachymski (IFT UW)

An introduction to quantum simulation

Join Zoom Meetinghttps://zoom.us/j/99427099542?pwd=WlNyNExXeG0zb0k2RXFUTjViQ083Zz09Meeting ID: 994 2709 9542Passcode: 3UQGcF

Quantum computers are often advertised as devices that canrevolutionize the society. However, the capability of near-termquantum devices is strongly limited by decoherence, operation errorsand low number of qubits. Quantum simulators, which do not aim to beuniversal, but rather focus on specific physical problems, are lessprone to errors and can offer better scaling. This research fieldcombines multiple disciplines, both very fundamental and more applied.In my talk, I would like to explain why this approach is needed,discuss some problems, for which quantum simulation can be a helpfultool and showcase physical platforms which are promising for thispurpose.