Lectures @ 14th HGSFP Winterschool 2022
Lectures will be given on four days in the morning and the afternoon and generally consist of two parts held on consecutive days. Every morning and afternoon session will have three lectures in parallel, thus every participant can choose two lectures to attend. Please note that it's not fixed yet which of the following lectures will be in parallel sessions. The general lecture will take place in a common session for all participants.
Hintereisferner - an uncalibrated (?) instrument in the Open Air Laboratory Rofental
(General Lecture, Rainer Prinz)
The Rofental catchment in the upper Ötztal offers hydro-meteorological data sets spanning a period of 150 years. Glaciological observations even date back to the early 17th century, hence providing an exceptional time series of high mountain observations. Climate change sciences require time series of glacier geometry and mass changes as essential data sources for model calibration and validation. The Rofental harbours 3 out of 40 global benchmark glaciers, which offer a continuous time series of mass change observations for more than 50 years. Throughout the history of glaciological research on Hintereisferner, two research approaches have been followed concurrently, measurements of processes and their modelling. Beside the operational glaciological and climatological studies, the glacier served as a testbed for glaciological, geophysical, geodetic, meteorological, climatological or remote sensing methods, which all require a controlled and calibrated environment. Traditionally, this was obtained by a dense network of automated meteorological measurements and event-based field surveys. In addition, we employ a worldwide unique, permanently installed terrestrial LIDAR for various purposes requiring high-resolution terrain representation. This combination of traditional long-term and modern high-resolution observations offers a major step forward in understanding high mountain environments from measurements and models including a transfer to data sparse regions.
Towards a Quantum Internet
(Tracy Northup)
What would it mean to have a "quantum internet"? What existing problems could such an internet solve, and what new opportunities would it offer? What are the challenges for quantum physicists on the road to this technology? In the first lecture, we will define a quantum internet and examine how this concept links the fields of quantum computing and quantum communication. We will consider the range of currently known applications, from quantum key distribution to distributed computing to networks of telescopes, and their underlying requirements. In the second lecture, we will discuss the various hardware platforms that are currently being studied for quantum network applications. After examining the state of the art, we will look at what advances we might expect to see in the coming decade.
Coherent Light Interacting with Nuclei: from Ultraviolet to Gamma Rays
(Adriana Palffy)
In the past decades, the interaction of optical coherent light (laser) with atoms and molecules has revolutionized atomic physics. Atomic nuclei proved to be less easy to tame due to the partial lack of coherent sources for the frequency regime of interest and their weaker coupling to the radiation field. However, appealing potential applications in coherent light interacting with nuclei exist along a broad range of parameters, from vacuum ultraviolet radiation to gamma rays. The lectures will address three examples covering this range. First, we will introduce current efforts to develop a novel ultra-precise clock based on a nuclear transition in 229Th driven with a vacuum ultraviolet laser. Moving towards higher energies, we will show how the cooperative effects occurring when x-ray radiation interacts with nuclei in a crystal lattice offer the possibility to put single x-ray photons on hold. Finally, the formation of compound nuclei in a parameter regime never available so far by coherent MeV photons as the ones envisaged at upcoming petawatt laser facilities will be discussed. These applications speak for the potential that coherent radiation may bring for controlling atomic nuclei.
Continuous Analog Quantum Simulation
(Helmut Strobel)
Quantum technology is on everyone's lips these days. However, the device which is most hoped-for as well as feared in this field, the universal quantum computer, is still in its infancy with many hurdles still to be taken until a relevant advantage comes into reach. This course gives an introduction to an alternative concerning fundamental physics questions -- analog quantum simulation -- mainly from the perspective of ultracold neutral atoms. Here, already nowadays nontrivial questions, which are beyond the reach of known numerical methods can be tackled with experimentally realized model systems in a highly controlled environment.
Cosmic Messengers in the Galaxy
(Fiorenza Donato)
We discuss the origin, the propagation and the information brought by cosmic particles measured at the Earth. Specifically, we treat the charged component in the cosmic radiation - protons, nuclei, leptons, antimatter - and discuss their link with the gamma rays. Possibly, in some of their fluxes, an exotic component due to dark matter annihilation could be hidden.
Causality and geometry in physics
(Björn Malte Schäfer)
Spacetime is a dynamic geometric object, and in this course we'll go through the influence of spacetime geometry on the motion of particles and fields, as well as its own geometric and dynamical properties. We'll encounter how horizons emerge and why black holes are (not so) black. Finally we'll see how Nature makes sure that spacetime is causal by design of its geometry.
Particle Dark Matter
(Susanne Westhoff)
Dark matter exists in the Universe, there is no doubt. But even after decades of research we do not understand its nature, nor its origin. In these lectures we will stress-test the hypothesis that dark matter is a new species of elementary particles. You will learn how to search for dark matter particles in the sky, on Earth and in underground experiments. Particle colliders play a special role in these searches, especially if dark matter interactions with visible matter are tiny.
The Physics and Future Prospects of State-of-the-Art and Emerging Photovoltaic Technologies
(Paul Faßl)
In the coming decades, solar cells will be one of the key cornerstones for the global transition to a carbon-free future with the global installed power capacity expected to increase from 630 GW at the end of 2019 to over 2 TW in 2030. In this talk, I will provide an overview of state-of-the-art solar cell technologies and continue with introducing the physics and challenges of emerging tandem photovoltaics that promise higher efficiencies at lower costs. Special focus will be given to novel hybrid organic-inorganic perovskite thin-film solar cells that could complement market-dominating silicon solar cells in silicon/perovskite tandem solar cells and in applications where flexible or semitransparent solar cells are required. The physics of semiconductors and their interfaces as well as the optics of solar cells will be covered in this lecture.
A physicist at the north pole: A story of radiative transfer in sea ice, the largest Artic expedition in history and new measurement technologies
(Christian Katlein)
Sea ice is a complex heterogeneous medium covering vast areas of our worlds polar oceans. It is both a key indicator of our planets climate and a key interface moderating climate-relevant fluxes of energy between atmosphere and ocean. Particularly the optical properties of sea ice determine the so-called ice-albedo feedback causing rapid changes in sea ice extent and thickness. This lecture will provide a basic introduction to the physical structure of sea ice, why and how the ocean freezes, as well as the most important processes governing its seasonal evolution. A particular focus will lie on the radiative transfer treatment in this complex highly scattering medium and its implementation in earth system models. In 2019 and 2020 the international Arctic drift expedition MOSAiC set out to repeat the historic drift of Fridtjof Nansen, investigating the Arctic Ocean from a boat frozen into the ice. The sea ice measurements carried out during MOSAiC as well as first results will be presented along with some insight into the harsh working conditions of a multi-month expedition into the polar night. The harsh climatic conditions of the polar regions also foster innovations in modern autonomous measurement techniques spanning from observation buoys to complex autonomous robotic underwater systems. Overall this lecture will hopefully provide insights into current research in sea ice science from multiple viewpoints of different scientific disciplines.
Numerical Modelling in Radiotherapy: Present and Future of Computational Radiation Treatment Planning
(Niklas Wahl)
Planning a radiation treatment is a delicate effort. Based on a tomography image, we want to find a radiation dosage that kills tumor cells while sparing the surrounding healthy tissue. Finding such a treatment plan requires numerical simulation of the dose deposited by ionizing radiation together with numerical optimization of the machine configuration. Both dose calculation algorithms and dose optimization techniques need to be computationally efficient, understandable, and reliable enough to work in a clinical environment. During the lecture we will find out how far we can and need to approximate the physics of dose deposition, how we can efficiently discretize the problem, and how different optimization techniques steer the decision-making process of complication probability v. tumor control. Finally, we will look into how new computational techniques, including AI, may transform radiotherapy treatment planning.