Vector Mesons interactions with nucleons are not known at all in a quantitative way. A new method developed in our TUM group, allows to make use of the copius data collected at the LHC with the ALICE experiment to identify vector mesons as phi and omega together with protons produced in pp and pPb collisions at energiey of the center of mass of 13 and 5 TeV.

The femotscopy technique allows then to extract the scattering parameters that governs the vector meson-nucleon interaction.

This kind of measurements have been not yet carried out by any experimental group yet but are highly important to undertand low energy QCD and hence strong interaction among hadrons.

The work implies programming in c++ but no prior experience is requested.

With solvent effects being central to several scientific disciplines like biology or (electro-)chemistry, computationally affordable methods are crucial to accurately simulate solvated systems. Implicit solvation models are widely used due to their simplicity and practical applicability in these kind of many-body problems. Here only the solute is explicitly modeled while the interaction with the solvent is coarse-grained into a continuum dielectric response, instead of considering individual solvent molecules. However, simply using the solvent medium’s experimental bulk dielectric constant neglects the fact that the behaviour of the solvent differs, sometimes drastically, in the vicinity of the solute compared to the bulk. Existing corrections to account for these entropic effects fail for charged systems and lack scientific foundation. These deficits of correctly accounting for multiple conformations in solution lead to great difficulties when calculating dissociation
constants (pKa values) or modeling other electrochemical processes using implicit solvation models.

The goal of this M.Sc. project is to introduce a better description that accounts for the orientational behaviour of solvent modecules, based on findings from previous extensive Molecular Dynamics simulations. The student will learn how to perform DFT calculations using implicit solvation and, in a second step, will compute the interaction of the interfacial water structure with the electric field obtained from these simulations. Basic knowledge of UNIX based operating systems and some experience with programming (and/or scripting) languages (preferably Python) is desirable, but not mandatory.
1

This Thesis is based on Deep Neural Networks (DNN) applied to generate new organic semiconductor (OS) molecules. Deep learning models project input data through several layers of nonlinearity and learn different levels of abstraction generating a link between the inputs and specific target outputs (or labels). Recently, there has been a fundamental work about using DNN algorithms for synthesising in-silico new OS [1] grounded on the seminal work by Gomez-Bombarelli et al. [2] and Kusner et al. [3] on the Grammar Variational AutoEncoders (GVAE) method. The thesis is focused on implementing a GVAE and further developing the method to include bigger molecules. The DNN will be applied to some realistic OS in order to evaluate the efficiency and accuracy in generating new molecules.

[1] P. B. Jørgensen et al., J. Chem. Phys., 148, 241735 (2018)

[2] R. Gómez-Bombarelli et al., Nat. Mat., 15, 1120-1128 (2016)

[3] M. J. Kusner, B. Paige, J. M. Hernández-Lobato, Grammar Variational Autoencoder, arXiv:1703.01925v1 [stat.ML] (2017)

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.

Für die Entwicklung von Theraphieansätzen ist es notwendig, die Wirkung von Medikamenten auf Organe zu untersuchen. Zu diesem Ziel werden inzwischen Organoide verwendet - das sind Organ ähnliche Zellverbände, die in einer 3d Zellkultur wachsen. Trotz der immensen Erfolge, sind ganz zentrale Fragen zu der Entwicklung dieser Strukturen weitestgehend ungeklärt. Im Rahmen der Arbeit sollen die physikalsichen Eigenschaften der Umgebung auf das Organoid-Wachstum untersucht werden. Es werden Mikrorehologische und Mikroskopsiche Methoden entwickelt und verwendet um die Abhängigkeit von Mikro-Umgebung auf Organoidentwicklung zu quantifizieren. 

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

Zur Verbesserung der Effizienz des Myontriggersystems des ATLAS-Detektors am Large Hadron Collider (LHC) werden neue schnelle Triggerdetektoren (Resistive Plate Chambers) gebaut, die sehr hohe Untergrundzaehlraten aushalten und hoehere Lebensdauer und Zeitaufloesung als bisher aufweisen. Die Eigenschaften dieser Detektoren werden in vorhandenen Testaufbauten und im Teststrahl am CERN systematisch untersucht.

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.

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. 

Deep eutectic solvents (DES) are a new class of designer solvents composed of hydrogen bond donor and hydrogen bond acceptor molecules. The mixture has a substantially lower melting point than the pure substances and remains liquid at room temperature. They may be called "green solvents". In the master thesis proposed, thermoresponsive polymers shall be studied in these solvents. In water, these are soluble up to a certain temperature, above which, they become water-insoluble. Since this behavior is strongly related to hydrogen bonds, new insight can be gained by using hydrogen bonding solvent.

In the thesis, the solubility behavior of switchable polymers in DES shall be studied using turbidimetry, dynamic light scattering and small-angle X-ray scattering. After a literature research, the sample preparation, measurement and data analyis shall be carried out. For more information, please contact Prof. Christine Papadakis, papadakis@tum.de.

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.

Der Large Hadron Collider (LHC) bietet eine einzigartige Gelegenheit, nach Teilchen der Dunklen Materie zu suchen. Sie machen sich im Detektor durch sogenannte fehlende Energie bemerkbar. Zusaetzlich muessen jedoch bekannte Teilchen als Signal erzeugt werden. Dafuer eignen sich besonders gut Hadronjets, die durch Gluonabstrahlung im Anfangszustand haeufig erzeugt werden, aber auch Eichbosonen und sogar das Higgs-Boson. Die Auswahlkriterien fuer solche Ereignisse werden mit Hilfe simulierter Daten optimiert.

The recent detection of gravitational waves (GW) with the advanced LIGO/Virgo instruments in conjunction with a short gamma-ray burst (GRB) has surprised gamma-ray astronomers because of the substantially different properties of the GRB signal as compared to canonical GRBs. This motivates an "open-mind" search for untriggered transient events in the data stream of the gamma-ray burst monitor (GBM) on the Fermi satellite. With two previous Bachelor theses we have developed a physical background model, paving the way for automated searches, and subsequent source and background fitting.

This thesis shall be devoted to establishing a Python program for identifying long-term (> few minutes) transients in Fermi/GBM data, localizing them on the sky, and deriving basic properties (spectrum, light curve). The project includes elements from computational and observational high-energy astrophysics, and will allow for obtaining extensive knowledge on the broad class of high-energy transients.

Some background in astrophysics is advantegeous, but affinity with Python programming is a must.

Contact: Jochen Greiner, jcg@mpe.mpg.de, MPE Room 1.3.13, Tel. 30000-3847

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.