At the Walter Schottky Institute (WSI-TUM) we recently launched a research project directed to the exploration of new types of high-efficiency solar cell systems based on 3D-structured III-V semiconductor nanowires.

Conventional single-cell photovoltaic devices are known to have performance limits due to large thermal and spectral losses, light trapping issues and charge carrier losses. To overcome these problems 3D-structured nanowire (NW) solar cells have emerged as promising systems with improved light trapping and absorption properties beyond the ray-optic limit, as well as better carrier collection efficiencies.

The goal of this M.Sc. project is to exploit the advantages of 3D-structured III-V semiconductor NWs and work towards a novel hot carrier solar cell (HCSC), which allows to selectively cool charge carriers and reduce thermal losses. Hereby, you will be closely working together with two PhD students to first design proper bottom-up III-V NW heterostructures from the group-III-V family of semiconductors. Exploiting the full geometrical and energy-selective parameter space, the design will be directly guided by in-depth simulations for enhanced photoabsorption and effective carrier thermalization properties. NW heterostructures on lithographically patterned substrates should then be realized by top-down/bottom-up nanofabrication processes and further characterized by various optical spectroscopy methods (photoluminescence, FTIR, and UV-Vis-NIR absorption spectroscopy). Finally, the goal is to identify correlations between array-geometry, NW dimensions, and electronic properties of the selected heterostructure material (band gap and strain) and the corresponding optical and charge carrier responses.

You will gain & learn:

• Knowledge in electromagnetic (FDTD) and electronic band structure simulations (nextnano)
• Advanced lithography / clean-room processes for state-of-the art 3D structured NWs
• Diverse optical spectroscopy (micro-Photoluminescence, FTIR, UV-Vis-NIR absorption)
• Correlated microscopy methods (SEM, He-Ion Microscopy)

Experience in the area of clean room fabrication, optical spectroscopy or nanoanalytics, as well as experience in simulations is a benefit, but secondary to motivation and commitment. Applications should be sent to Gregor.Koblmueller@wsi.tum.de and Jonathan.Finley@wsi.tum.de. Please include your CV, and a transcript of records (Bachelor & Master).

May 2019

Scientific motivation: 

What is the mass of the neutrino? This is one of the most fundamental open questions in Astroparticle Physics today. We know from neutrino oscillations that neutrinos must have a mass, but its actual value is still unknown. The knowledge of the neutrino mass would be an important key to understand the formation of structures in the early universe and it could help to shed light on the fundamental origin of masses.

The Karlsruhe Tritium Neutrino (KATRIN) experiment is a direct neutrino mass experiment, which is designed to determine the neutrino mass via a precise measurement of the tritium beta decay spectrum. KATRIN just started data taking in April 2019. The goal is to reach a sensitivity to the neutrino mass of 200 meV after 3 years of data taking. So, right now is the perfect moment to join the experiment!

Thesis Topic:

In this Thesis project you participate in the analysis of the KATRIN data. A key aspect of the analysis is the understanding of systematic uncertainties and their impact on the neutrino mass. 

One of the most critical systematic uncertainties arises from the 10-m long tritium source. The gaseous source can be thought of as a plasma which exhibits a certain plasma potential. In KATRIN, we characterize this electric potential with the help of a krypton calibration source. 

The main task of the Thesis project is the analysis of the krypton calibration campaign. The goal is 1) to determine the key parameters of the source plasma, which are then used as input parameter for the neutrino mass analysis and 2) to  investigate the impact of the associated systematic uncertainties on the neutrino mass fit. You will also have the chance to participate in the actual data taking phase onsite at the KATRIN experiment. 

You will gain & learn: 

• Participate in world-leading experiment to directly determine the neutrino mass

• Learn about astroparticle physics 

• In-depth knowledge on data analysis

• Programming in C++ and Python

• Work in a fun team with lots of social events

Bereits unsere eigene Existenz gibt einen Hinweis auf “neue Physik”. Die sichtbare Materie besteht aus Teilchen (nicht aus Antiteilchen), sodass während der Evolution des Universums zu einem bestimmten Zeitpunkt diese Asymmetrie zwischen Materie und Antimaterie durch einen bisher unbekannten Mechanismus hevorgerufen worden sein muss. Durch verschiedene experimentelle Daten können wir diese Asymmetrie sogar genau quantifizieren.

Die Emmy-Noether Gruppe “Baryogenese, Dunkle Materie und Neutrinos – Umfassende Analysen und präzise Methoden in der Teilchenkosmologie” unter der Leitung von Dr. Julia Harz befasst sich unter anderem mit der Fragestellung wie wir dem Mechanismus hinter der Baryonasymmetrie näher kommen können.

Im Rahmen dessen biete ich Masterarbeiten zu diesem Thema an:

(1) Eine mögliche Arbeit würde sich mit einem etabliertem, teilchentheoretischem Modell befassen, welches verschiedene offene Fragen (Dunkle Materie, Inflation, Baryogenese, Neutrinomassen etc.) addressiert. Dieses Modell soll mit einem sogenanntem globalen Fit in seinem Parameterbereich eingeschränkt werden. Das Projekt würde in internationaler Kollaboration stattfinden, während sich die Masterarbeit selbst auf den Bereich der Baryogenese fokusieren würde. Für diese Arbeit wären Programmierkenntnisse wünschenswert bzw. die Motivation solche selbständig zu erlernen.

(2) Eine zweite mögliche Arbeit würde sich mit der Möglichkeit beschäftigen, verschiedene Baryogenesemodelle mit Messungen am Large Hadron Collider zu testen. Für diese Arbeit wären fundierte, analytische Kenntnisse wünschenswert bzw. die Motivation sich mit ‘pen and paper’ in Rechnungen einzuarbeiten.

Scientific motivation: 

Does there exist an undiscovered type of neutrino, a so-called sterile neutrino? Could this particle be the Dark Matter? These are among the most topical open questions in Astroparticle physics at the moment. 

The aim of the TRISTAN project, is to develop a novel multi-pixel Silicon Drift Detector system to upgrade the KATRIN apparatus. This upgrade would allow the  KATRIN experiment to search for this hypothetical new particle. 

Thesis Topic:

The topic of this Thesis project is the characterization of the next-generation TRISTAN prototype, which will be ready for testing in September 2019. The goal of this project is a detailed understanding of the detector response to photons and electrons. For this purpose you will perform measurements with x-ray calibration sources and with an electron microscope at the Semiconductor Laboratory of the Max Planck society in Munich. For this purpose a dedicated test stand has to be designed and fabricated. The measurements and data analysis will be complemented with detailed Monte Carlo simulations of the particle interactions in the detector and the signal generation. 

You will gain & learn:

• Learn about astroparticle physics 

• Detailed understanding of semiconductor detector technology

• Expertise in experimental hardware work 

• Programming in Python and C++

• Work in a fun team with lots of social events

The proton is one of the primary building blocks of all matter in the visible universe and as such is at the core of the quest for understanding nature. Yet, many of its properties are not well understood. At the center of current interest stands its charge radius, oftentimes simply referred to as the proton radius. Recent measurements of this fundamental quantity are in significant disagreement with each other, in what is often called the proton radius puzzle.

As part of an international collaboration, we intend to measure the proton radius through elastic muon-proton scattering with a high-energy muon beam at CERN’s Super Proton Synchrotron starting in 2021. The experiment requires the development of several new particle detectors, among them a fast tracking detector made of scintillating-plastic fibers. The construction and test of this tracker is the main objective of this thesis.

Tasks

• Acquire the necessary understanding of the fundamentals of particle detection, scintillating materials, photodetectors, and detector read-out electronics.
• Perform initial tests of detector components in the laboratory environment.
• Design, construct, and commission three prototype detectors.
• Conduct a system test at the MAMI accelerator facility in Mainz.
• Analyze the performance of the tracker system.

What We Offer

We offer you to make your contribution to a new experiment trying to solve one of the most puzzling discrepancies in our understanding of the nature of matter. You will gain experience in detector design, electronics design, and data analysis. And you will get the chance to perform an experiment at a particle accelerator facility!

Chemische Prozesse an Oberflächen wollen verstanden werden. Wir verwenden modernste Methoden der magnetischen Resonanz, um solche Elementarprozesse zu beobachten, bei denen Spins eine Rolle spielen. Untersuchungsobjekte sind hochaktuelle oxidische Materialien für die Photokatalyse, die wir mit Hilfe von elektrisch und optisch detektierter magnetischer Resonanz studieren werden. Sie erlernen die Herstellung und Charaktersisierung dieser Materialien, das Arbeiten mit Kryostaten und Lasern, sowie die Grundlagen und Anwendungen der Elektronenspinresonanz.    

The RadMap Telescope is a TUM-led NASA experiment that will monitor the radiation background on the International

Space Station (ISS). The instrument incorporates several state-of-the-art particle detection technologies and has a

scintillating fiber tracker at its core. As part of this thesis, an existing prototype tracker shall be analyzed and a new,

modular stacking concept shall be developed, constructed, and tested.

Your Tasks

Depending on the time available for your thesis, your work could include some or all of the following tasks:

Familiarize yourself with the working principle of the fiber tracker and associated hardware.

Learn how to use 3D CAD software (SolidWorks) and 3D printers.

Analyze the current tracker prototype from a hardware perspective and identify weak spots in the design.

Support testing of the existing prototype using radioactive sources.

Develop a new, modular stacking concept whose parts can be manufactured on a 3D printer.

Build, evaluate, and test prototype modules.

Support the development, construction, and test of the final flight model.

Prerequisites

Experience in 3D CAD design and/or manufacturing techniques is helpful, but not required. You should enjoy working in

the lab and interacting with a young and dynamic team.

Contact

If you are interested in learning more about this opportunity, please contact

Prof. Laura Fabbietti (laura.fabbietti@ph.tum.de).

Gas Electron Multipliers (GEMs) are used to multiply incoming electrons to enable the detection of originally small amounts of charge. Thick GEMs (THGEMs) are a robust variation of GEMs. With thickness, hole size, and hole pitch being one order of magnitude larger than in standard GEMs, THGEMs offer more stability against mechanical stress and contamination by dirt. Therefore, they are suited for operation in much harsher environments and form an interesting alternative for a variety of applications.

A novel and innovative method of photodetection is to use a THGEM coated with a material with a low working function (e.g. CsI). Electrons from the top coating are released by incoming photons and can be multiplied by the THGEM for readout. This device offers the possibility for relatively cheap large scale applications, which is particularly advantageous for neutrino detectors.

The student will take part in the coating process of THGEMs and extensive R\&D studies in order to proof the feasibility of this kind of technology.

Angular momentum transport in magnetically ordered insulators is carried by magnetic excitation quanta in contrast to magnetic conductors, where mobile charge carrier also carry angular momentum. In magnetically ordered insulator/normal metal hybrids it is possible to study the transport of angular momentum by all-electrical means via the spin Hall and inverse spin Hall effect in the normal metal. The focus of this project is the investigation of possibilities to manipulate the angular momentum transport in the magnetically ordered insulator by electrical means and by finite size effects. In addition, another goal is the enhancement of the sensitivity of the currently existing measurement setup and the realization of new measurement protocols in hard- and software.

An ambitious master student with good analytical skills is required to carry out these experiments on all-electrical magnon transport. One part of the thesis is the fabrication of nanometer sized devices for the experiments via electron beam lithography and UHV sputtering. The properties of these devices will be analyzed using magnetotransport experiments in superconducting magnet cryostats. Another important aspect is the realization of more sophisticated measurement methods, aiming for a enhancement in sensitivity, a better signal-to-noise ratios and a higher versatility of the measurement protocols

Fuer die Myondetektoren der Experimente am Large Hadron Collider (LHC) und an zukuenftigen hochenergetischen Proton-Collidern werden Gasdetektoren benoetigt, die auch bei sehr hohen Unter-grundzaehlraten hohe Ortsaufloesung und Myonnachweiswahr-scheinlichkeit liefern. Fuer die im Bau befindlichen Myonkammern wird neue Ausleselektronik benoetigt, die maximale Ratenfaehig-keit erlaubt. Hierzu werden neue Verfahren zur schnellen Pulsformung im Labor und im Teststrahl am CERN untersucht. Parallel dazu werden die Schaltungen als ASIC Chips realisiert und getestet.

One of topical issues of the modern condensed matter physics is the interplay between superconducting and insulating instabilities of the normal metallic state in materials with strong electronic correlations. Organic metals and superconductors, thanks to their high crystal quality, simple conduction bands, and a great diversity of electronic states, offer a perfect laboratory for studying fundamental problems of the correlated electron physics. A member of the κ-(ET)₂X family to be studied in this Master thesis is believed to represent a novel state of matter, quantum spin liquid at ambient pressure. Under a moderate pressure of about 3 kbar the material becomes metallic and superconducting.

The aim of the work is to trace the evolution of the electronic properties, particularly, of correlation effects, in close proximity to the metal-insulator phase boundary. The position with respect to the phase boundary will be precisely tuned by applying quasi-hydrostatic pressure. Magnetoresistance and especially its quantum oscillations in strong magnetic fields will be used to probe the electronic properties of the system. Observation of the oscillations requires sufficiently low temperatures which will be achieved by use of a ³He cryostat (down to 0.4 K) and of a ³He-⁴He dilution refrigerator (down to below 100 mK). A part of the experiment will be done at the European Magnetic Field Laboratory in steady fields up to 30 T or in pulsed fields up to 80 T. The experimental results will be analyzed in comparison with recent theoretical predictions of correlation effects and violations of the Fermi-liquid behavior in proximity to the spin-liquid Mott-insulating state.

Physics: Correlated electron systems; metal-insulator transition; magnetic quantum oscillations; unconventional superconductivity.

Techniques: Strong magnetic fields; high pressures; cryogenic (liquid ⁴He; ³He; dilution fridge) techniques; high-precision magnetoresistance measurements.

Contact person: Mark Kartsovnik (mark.kartsovnik@wmi.badw.de)

Multifunctional materials combining nontrivial conducting and magnetic properties are one of hot topics in the modern condensed matter physics. Prominent examples are charge transfer salts of the organic donor BETS with anions containing a transition metal. They represent perfect multilayer structures of conducting and magnetic subsystems separated on a nanometer scale. The interplay between the two subsystems results in a variety of electronic and magnetic ground states depending on subtle chemical substitutions as well as on external magnetic field and pressure. The goal of this master thesis is a quantitative study of the interaction between the itinerant electrons and localized spins in the antiferromagnetic superconductors (BETS)₂FeX₄ with X = Cl, Br. To this end, comparative measurements of quantum oscillations in the magnetoresistance and magnetization will be carried out at strong magnetic fields, at temperatures down to 0.4 K. The results will be analyzed in terms of the exchange field dependent spin-splitting effect in a quasi-two-dimensional metal.

Physics: Correlated electronic systems; magnetic ordering and superconductivity; magnetic quantum oscillations.

Techniques: Strong magnetic fields; magnetotransport; magnetic torque; cryogenic (liquid 4He and 3He) techniques.

Contact person: Mark Kartsovnik (mark.kartsovnik@wmi.badw.de)

The computational design of new materials for heterogeneous catalysis relies on methods that can accurately predict adsorption energies of reactants and intermediates at low computational cost. Quantum-mechanical calculations based on the Density Functional Theory (DFT) are typically used for surface reactivity studies, but their cost significantly limits the number of compounds that can be evaluated as candidates for catalysing each targeted reaction. Scaling relations between adsorption energies of similar adsorbates and machine-learning approaches have been recently developed to circumvent this computational burden, but their application is currently limited to extended close-packed metal surfaces. Real catalysts are typically formed by supported metal nanoparticles exposing sites at different facets, edges, and corners. Dealing only with extended surfaces thus limits the predictive potential of computational catalyst design.

The goal of this M.Sc. project is to extend existing approaches for predicting adsorption energies to the description of undercoordinated sites typically found on metal nanoparticles. The candidate should be interested in electronic structure and machine learning methods, as well as in surface chemistry and catalysis. The student will learn how to perform DFT-based calculations and to use and asses the results of different machine learning methods. Basic knowledge of UNIX based operating systems and some experience with programming (and/or scripting) languages (preferably Python) is desirable, but not required.

Questions about the project can be directed to mie.andersen@ch.tum.de and albert.bruix@ch.tum.de. 

 Our Group at the Technische Universität München (TUM) studies the properties of hadronic interactions and their implications for astro-particle physics by means of accelerator experiments. 

One of the indirect ways to search for dark matter (c) is to look for 𝜒𝜒̅ annihilations resulting in final states such as 𝑝𝑝̅,𝑒+𝑒−,𝑑𝑑̅…with satellite or balloon experiments. In particular, low energy 𝑑̅ seem to be optimal candidates for such searches, since cosmic ray-induced background does not contribute too much to this final state. 

In order to estimate a reliable detection probability of dark matter-induced events such as 𝜒𝜒̅⟶𝑑𝑑̅+ .., the interaction probability of 𝑑̅ with normal nuclear matter must first be measured. The latter will indeed drive the detection probability of antiparticles in the spectrometers. 

Since the 𝑑̅+𝐴 (𝐴=𝐶,𝐴𝑙,𝑆𝑖..) elastic and inelastic cross-sections for 𝑑̅ with energies lower than 6 GeV is completely unknown, the topic of the advertised PhD deals with the measurement of these interactions. 

This is made possible by analyzing pp collisions at √𝑠=13 𝑇𝑒𝑉 at the LHC measured by the ALICE detector, since in these collisions a large statistics of 𝑝̅ and 𝑑̅ is produced and their interaction with the detector material can be studied. 

The Master Thesis work will be structured in the following way: 

* Determination of the  𝑝̅/p and  𝑑̅ /d experimental ratios as a function of the particle momentum, extracted from pp collisions measured by ALICE at  √𝑠=13 𝑇𝑒𝑉

* Comparison of the experimental ratio to GEANT4 simulations

* estimation of the 𝑑̅+𝐴 (𝐴=𝐶,𝐴𝑙,𝑆𝑖..) cross sections.

Das COMPASS-Experiment am Super-Proton Synchrotron SPS des CERN führt seit etwa 18 Jahren Messungen mit hochenergetischen Teilchenstrahlen zur Erforschung der Quantenchromodynamik stark wechselwirkender Teilchen durch. Zur Zeit wird das Nachfolge-Experiment COMPASS++/AMBER entworfen, mit dem unter anderem eine Präzisionsmessung von elastischer Myon-Proton Streuung durchgeführt werden soll. Durch die besonderen kinematischen Verhältnisse wird diese Messung allgemein als wichtige zusätzliche Informationsquelle anerkannt, um die derzeit widersprüchlichen Ergebnisse zur Bestimmung des Protonradius besser zu verstehen und so zur Lösung des Protonradius-Rätsels beizutragen.

Für dieses Experiment sind einige neue Detektortypen geplant, darunter ein aktives Wasserstofftarget mit Driftzeit-Projektionstechnik und Pixel-Siliziumdetektoren. Der Aufbau, der 2021 in Betrieb gehen soll, befindet sich derzeit in Optimierung, wozu auch zeitaufwändige und komplexe Monte-Carlo-Simuationen durchzuführen sind. Hier soll im Rahmen dieser Arbeit mitgearbeitet werden, was eine spannende und in aktuelle Forschungsaktivitäten eng eingebundene Tätigkeit verspricht. 

In this project, we aim to fabricate and investigate novel organic-inorganic hybrid materials for thermoelectric applications. The goal is to realize efficient low temperature (T < 100°C) thermoelectric thin films and coatings which can contribute for example to energy efficient buildings. By combining nanostructured inorganic materials with conducting polymers a novel approach for this class of materials shall be realized. Possible inorganic nanomaterial components include Silicon nanocrystals (either undoped, n-type or p-type doped) as well as other nanoparticles. Different polymer materials such as the polymer blends of conjugated polymers, which can be tuned in conductivity and in its nanostructure, shall be used as the organic partner in our hybrid approach.

Organic photovoltaic (OPV) technology has seen a rapid evolution over the last decade. The unique selling points of OPVs, such as excellent light harvesting capability, freedom of form, color and transparency, environmental friendliness, easy scalability and lower manufacturing costs based on roll-to-roll printing methods, position this technology for the mobile power market, and this most properly reflects the state of the art in commercialization. An important milestone towards OPV commercialization has been surpassed by reaching a power conversion efficiency (PCE) of up to 17%. The main limitation in OPVs is due to the intrinsic narrow absorption window (~100-200 nm) of polymers compared to inorganic semiconductors such as Si, which makes it challenging to fully cover the solar spectrum with a single junction device. To overcome the absorption limitation, ternary blend organic solar cells represent one of the dominant strategies that has been explored in the last decade. The outstanding advantage of ternary blends consists of maintaining the simplicity of the processing conditions used for single active layer devices. Interestingly, the open circuit voltage (Voc) is tunable depending on the loading concentration of the ternary compound in both ternary systems compromised of i) two donors and one accepter as well as ii) one donor – two accepters blends.

The origin of the composition-tunability of Voc and the optimal electronic correlations between the components remains as an open question in OPV field. Obviously, it is very challenging to develop a complete model for Voc in ternary systems mainly due to the fact that this model should take all the electronic interactions between the components into account and consider their role in the photogeneration. Moreover, the model should be compositional dependent and accounts for the different microstructures and transport mechanisms operating simultaneously in the system. To this end, a semi-empirical method is required to link the electrical characteristics of ternaries to their morphological properties and draw a comprehensive picture from the morphology models reported in literature as the origin of Voc changes in ternary systems.

This project will focus on solving the aforementioned key challenge by employing a semi-emprical method based on kinetic Monte Carlo (kMC). An existing lattice kinetic Monte Carlo model, previously applied to the modeling of binary polymer:fullerrene solar cells, will be extended to treat ternary blends. This will allow us to correlate nano-morphological features with measured optical properties and obtained Voc, a crucial capability for the design of optimized, high performance ternary solar cells. 

Quantum optics is an extremely powerful approach towards quantum communication, quantum sensing, and quantum computing. In particular, quantum information stored in photons has very low decoherence and can be transmitted over large distances through optical fibers. To date, most experiments in quantum optics use optical tables full with mirrors and beam splitters that all have to be carefully aligned and stabilized. This may be good enough for initial demonstrations, but in order to bring quantum science into the realm of quantum technology, a more scalable approach is required.

With our expertise in making photonic chips using advanced nanofabrication, we are making putting these exciting quantum optics experiments on chips. Here, light is routed via optical waveguides. Furthermore, by bending a waveguide, one gets the equivalent of a free-space mirror; a beam splitter cube becomes a directional coupler and so on. By combining these elements, we can make the building block for e.g. an optical quantum computer. With that, the possibilities are almost unlimited.

For such large-scale optical quantum circuits we also want to incorporate single-photon sources, superconducting single-photon detectors, and optomechanical phase shifters. This all happens on a single chip. Making and characterizing the components is the first step and from there on, you are making more and more complex quantum chips. You will be doing the nanofabrication in the cleanroom, and then use our optical measurement setups to see how each device is performing. Depending on your preference, it may also be possible to add a modelling component to the project.

See http://www.groups.ph.tum.de/en/qtech/openings/ for a detailed description of this project.

Fully merging thefields of integrated electronics and photonics is the major goal of distributed information processing today. However, a fundamental bottleneck is that cubic Si and Ge are both indirect bandgap semiconductors, which cannot emit light efficiently. Achieving efficient light emission from group-IV materials has been a holy grail in silicon technology for decades, but despite tremendous efforts, this has not been achieved.  Recently, the hexagonal crystal phase of Ge has been predicted to be a direct gap semiconductor, opening up a new route to achieving efficient light emitters on the basis of group IV semicodnuctors.  Growing hexagonal Ge and SiGe is non-trivial, but recently our collaboration partners have succeded.

In this thesis you will work as part of a team in close collaboration with several research groups from the Netherlands, U.K., Austria and Switzerland. You will perform spatially resolved optical spectroscopy on hex-Ge and SiGe nanowires to test the nature of their electronic bandstructure, increase the efficiency of their emission and, hopefully, demonstrate that they are indeed capable of emitting light efficiently.  You will learn about (near)infrared optics, cryogenics and contribute to this exciting research field.  You should be highly motivated, have ambition to work in a leading experimental physics group and sometimes willing to travel to consortium meetings to help discuss our results.

Interested ?  Contact Prof Finley or David Busse for more information on the thesis and to look around our laboratories.

In recent years, the plan of sending human back to the Moon came back to the fore. Some ambitious plans even consider building a permanently inhabited base on the moon. However, the radiation environment on the Moon can be a problematic health issue for the astronauts. Only little data is available from the Moon’s surface and the effect of particles that are produced in the upper layers of the lunar surface by the bombardment of cosmic rays is not yet fully understood. In this thesis, a full simulation of the lunar radiation environment shall be conducted. A detailed simulation of the galactic cosmic-ray background interacting with the Moon’s regolith shall be conducted using the high-energy physics simulation tool Geant4. The outcome of this study shall be used to set requirements for radiation detectors that shall measure all contributing radiation components. These results shall be used to optimize the design of the radiation detector currently under development for the LUVMI-X moon rover. 

Tasks

• Acquire the necessary theoretical understanding of the radiation environment in space and the interactions of cosmic rays with matter.
• Set up a simulation written in C++, based on the Geant4 simulation framework.
• Analyze and interpret the simulated radiation environment.
• Optimize the design of a particle detector that can efficiently measure the lunar radiation environment.  

Prerequisites 

Experience in C++ programming is helpful, but not required.

Contact

Thomas Pöschl, Room PH1 3257, Thomas.poeschl@ph.tum.de

Martin Losekamm, Room PH1 3257, m.losekamm@tum.de

Prof. Stephan Paul, Room PH1 3263, stephan.paul@tum.de

The IceCube detector at the South Pole is the largest operating neutrino telescope on the planet. With an uptime of close to 100%, this detector is setting an example for the rest of the neutrino astronomy community in both detection hardware and maintenance. One aspect that has been dominating the capabilities of IceCube the past years are systematic uncertainties resulting from not optimal calibration measures. These experimental systematics will be addressed in the IceCube Upgrade (ICU) scheduled for 2022 with a deployment of 7 new strings with calibration instrumentation and a focus on low-energy extension of the detector.

In the scope of a master / bachelor's thesis, a student will contribute to study the recalibration of IceCube systematics using a calibration instrument developed within the ECP chair (POCAM) that will be deployed within the ICU and act as an independent isotropic light source. An existing GEANT4-based simulation code has been developed that will be able to study the systematic effects of different observables within the ice using the POCAM. If the student is able to program (C++. python, bash) this will accelerate the process but is certainly not a stringent requirement.

Viele Erweiterungen des Standardmodells sagen neue schwere Resonanzen voraus, die in Bosonpaare, ZZ, WW, WZ, HZ, HW zerfallen. Mit Hilfe simulierter Daten werden die Selektionskriterien fuer diese Zerfaelle optimiert und die Nachweissignifikanzen bestimmt. Die Ergebnisse werden auf die neuesten Daten des ATLAS-Experiments bei der bisher hoechsten Proton-Proton-Kollisions- Energie von 13 TeV bestimmt.

Synchronization is a universal phenomenon that is knows since they days of Huygens. When two or more oscillators with slightly different frequencies are coupled, they will start to move in phase. We can create small mechanical devices using advanced nanofabrication techniques here on campus. By sending light of the right wavelength, they start to oscillate, and when increasing the power the optomechanical coupling synchronizes them. The goal of this project is to synchronize devices made from silicon nitride, which is a special material with a lot of stress in it, and to increase the number of synchronized oscillators. The larger the system becomes, the richer the nonlinear dynamics will become. You will first make the devices in the cleanroom, measure them, and analyze the data.

See http://www.groups.ph.tum.de/en/qtech/openings/ for a detailed description of this project.

Semiempirical electronic structure approaches like the density functional tight-binding (DFTB) method are popular due to their unrivaled computational efficiency. This often makes them the only option, e.g. for describing the electronic structure of nanoparticles, which may consist of tens of thousands of atoms. Their efficiency comes at the cost of limited accuracy and transferability, however. Currently, these shortcomings are compensated on a case-by-case basis by the introduction of empirical parameters. Unfortunately, even here the limitations of the underlying theory sometimes become evident.
The goal of this M.Sc. project is the development of a novel framework for a tight-binding-like theory that goes beyond the typical two-center approximation for the Hamiltonian. The candidate should be interested learning the fundamentals of electronic structure theory, implementing methods and performing numerical test of different approximations. The main focus of the work will be on programming. Experience with a scripting language (e.g. Python) is advantageous but not mandatory. Questions about the project can be directed to johannes.margraf@ch.tum.de.
     

Disorder has a drastic influence on transport properties. In the presence of a random potential, a system of electrons can become insulating; a phenomenon known as many-body localization (MBL) that has been envisioned by the Nobel laureate Phil Anderson. However, even beyond the vanishing transport such systems have very intriguing properties. For example, many-body localization describes an exotic state of matter, in which fundamental concepts of statistical mechanics break down. In this project we will explore these exciting aspects of many-body localization.

Our lab is using solid state qubits to build sensors, for instance for magnetic fields. We aim to apply them to various applications, with a particular focus on life sciences.

We are seeking a MSc student to study a novel application, imaging of electric action potentials of neurons, the cells performing computation in the brain. This should involve the development of a new type of sensor, based on solid state quantum materials, smart signal processing by artificial neural networks, or a combination of both.

Techniques:

* You will learn to prepare microscopy samples of both solid state samples and cell cultures. 

* You will design an experiment to detect the weak optical signals from these samples in one of our existing microscope setups. This will involve development of advanced optics and control software.  

Depending on preference you will either

* Study fluoresent quantum materials like red fluorescent diamond and their response to external electric fields. 

* Develop signal processing protocols to enhance these signals in existing devices