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Breitbandiges dispersives Auslesen von supraleitenden Qubits |
Gross |
- Research group
- Technical Physics
- Description
-
An essential step for implementation of quantum computing architectures is an efficient readout of qubits. In the field of superconducting quantum circuits, this is typically realized by dispersively coupling a superconducting qubit to a microwave resonator. Then, the frequency of the resonator depends on the state of the qubit. The former can be extracted by probing the resonator with a coherent tone. However, efficiency of this readout approach is fundamentally limited by quantum laws. The corresponding threshold is commonly known as the standard quantum limit and bounds quantum efficiency of the readout process by 50%. Nevertheless, recent investigations have shown that it is possible to circumvent this limit and reach quantum efficiency of the qubit readout of 100% by exploiting broadband readout signal combined with Josephson parametric amplifiers.
The goal of this Master project is to build a proof-of-principle experimental setup and perform microwave cryogenic measurements on a superconducting transmon qubit in the broadband regime in order to demonstrate violation of the standard quantum limit in the dispersive readout.
- Contact person
- Michael Renger
- Kirill Fedorov
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Characterization and fabrication of superconducting multi-qubit devices |
Filipp |
- Research group
- Technical Physics
- Description
Superconducting quantum circuits form the basis of current quantum processing platforms that allow to run first algorithms. However, to make practical use of coherent quantum systems, there is considerable fundamental challenges ahead: overcoming decoherence of qubits caused by interactions with an uncontrolled environment, improving qubit control to avoid systematic errors, developing scalable multi-qubit architectures while maintaining high level of coherence, or the efficient generation of highly-entangled quantum states in quantum-classical hybrid schemes.
In this project, we plan to design and fabricate high-coherence superconducting microwave circuits (qubits and couplers) that allow for multi-qubit operations and therefore enhance the connectivity of a quantum processor. The characterization of these circuits in a cryogenic microwave measurement setup is an integral part of the project. The master project also consists of fabrication of the circuits using state-of-the-art micro- and nanofabrication techniques.
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Charakterisierung des Prototyps für ein Quantum Local Area Network (Q-LAN) |
Deppe |
- Research group
- Technical Physics
- Description
-
Quantum technologies are on the verge of revolutionizing high-security communication owing to advanced protocols such as teleportation and remote-state preparation. Development of quantum local area networks (QLAN) is an important milestone in this field. Such a microwave QLAN can be realized as superconducting transmission line cooled down to millikelvin temperatures. In practice, this system requires careful characterization measurements with quantum signals propagating over the cryogenic link in order to determine the effective losses, noise level, and other imperfections.
In this work, the main goal is to investigate a new prototype of a quantum local area network (QLAN) established between two neighboring laboratories. This includes analysis of experimental results with theoretical and numerical methods. This project will provide you an excellent opportunity to gather expertise in a broad range of topics from quantum physics to microwave engineering and cryogenic techniques.
- Contact person
- Matti Partanen
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Durchstimmung der Amplitude des Spin-Hall-Magnetwiderstands (topic is not available any more) |
Gross |
- Research group
- Technical Physics
- Description
The exchange of spin angular momentum between the localized magnetic moments of a magnetically ordered insulator and the spin polarization of the conduction electrons in an adjacent metallic electrode with large spin-orbit coupling gives rise to interfacial spin mixing. This manifests itself as a characteristic angular dependence of the metal’s resistivity on the magnetization direction of the insulator’s magnetic sublattices, denoted as “spin Hall magnetoresistance (SMR)”. The effect was first observed in ferrimagnetic Y3Fe5O12/Pt thin film heterostructures and recently also reported in antiferromagnetic NiO/Pt and α-Fe2O3/Pt. While the phase of the SMR oscillations is well understood and explained by theory, their amplitude, however, is still a matter of debate, since various extrinsic as well as intrinsic parameters play a crucial role. The goal of this master’s thesis is to study the correlation of the SMR amplitude to the density of magnetic ions and their spin magnetic moments in different magnetically ordered insulating oxides.
We are looking for a master student interested in thin film technology for the fabrication and investigation of magnetic insulator/normal metal bilayer structures. The master project will provide a comprehensive introduction into laser molecular beam epitaxy (laser-MBE) as well as electron beam physical vapor deposition, high-resolution X-ray diffraction (HRXRD), atomic force microscopy (AFM), superconducting quantum interference device (SQUID) magnetometry, photolithography, and angle-dependent magnetotransport measurements. - Contact person
- Matthias Opel
- Stephan Geprägs
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Elektronenspindynamik in einer stark koppelnden Umgebung |
Hübl |
- Research group
- Technical Physics
- Description
Modern quantum circuits allow to study strong light-matter interaction in a variety of systems. This so-called strong-coupling regime is key for many aspects of quantum information processing. This project focusses on strong coupling between a paramagnetic electron spin ensemble and a superconducting microwave resonator. Strong coupling is an established phenomenon in this system. However, many aspects regarding the dynamics of this coupled system as well as the non-linear response properties are not fully understood, yet, and we will address these aspects within this project. For this project, we will use superconducting microwave resonators based on NbTiN and spin paramagnetic spin ensembles of phosphorous donors and erbium centers in silicon.
We are looking for a highly motivated master student joining this project. Within your thesis, you will address questions regarding the dynamic response of a strongly coupled system based on a paramagnetic spin ensemble and a microwave resonator. In this context, you will fabricate and optimize microwave resonators and operate them at cryogenic temperatures. In addition, you will use complex microwave pulses, to control the coupled system and experimentally investigate its dynamical response. Within the project, you will learn how to fabricate superconducting microwave resonators in our in-house cleanroom and how to synthesize microwave pulses using arbitrary waveform generators - Contact person
- Rudolf Gross
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FPGA-basiertes Rückkopplungsverfahren für die Mikrowellen-basierte Quantenkommunikation |
Gross |
- Research group
- Technical Physics
- Description
-
Quantum experiments often require fast and versatile data processing which allows for a quantum feedback operation. This approach opens the road to many fascinating experiments such as quantum teleportation, entanglement purification, quantum error correction, among others. Here, we would like to develop a specific measurement and feedback setup, based on a field programmable gate array (FPGA), for experiments with propagating quantum microwaves.
The main goal is to program and experimentally test a specific image for an FPGA which would allow for acquisition of microwave signals and feedback generation over few hundred of nanoseconds. This timescale is the prerequisite for exploiting quantum correlations effects for quantum communication and cryptography protocols with propagating squeezed microwaves which are conducted in our lab. This project will offer a deep insight into the state‑of‑the‑art FPGA devices, microwave measurements, and cryogenic experiments with superconductors.
- Contact person
- Michael Renger
- Kirill Fedorov
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Herstellung von verlustarmen Josephson-Kontakten für Quanten-Bauelemente |
Deppe |
- Research group
- Technical Physics
- Description
-
Josephson junctions (JJs) represent a fundamental building block of modern quantum circuits such as superconducting qubits or Josephson parametric amplifiers. The JJs are conventionally fabricated with Al while the surrounding quantum circuits are often made of Nb. Henceforth, there is a need of galvanic connection between them which includes removing Nb oxide via ion milling. As a consequence, one needs to develop a careful milling and fabrication technique in order to preserve a low-loss microwave environment in the close vicinity of JJs. This task is of paramount importance for achieving high coherence times of the related quantum devices.
The goal of this Master project is to develop a fabrication technique for Al/Nb superconducting circuits which will include Ar/O2 milling. This also includes cryogenic microwave studies of fabricated superconducting circuits (such as Josephson parametric amplifiers and transmon qubits) and participation in experiments towards quantum information processing with superconducting devices.
- Contact person
- Yuki Nojiri
- Kirill Fedorov
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High frequency optomechanical devices for quantum optomechanics |
Poot |
- Research group
- Quantum Technologies
- Description
The smaller a device is, the higher its resonance frequency becomes. For our future quantum optomechanics experiments we will be working with mechanical resonators that operate at GHz frequencies and simultaneously couple strongly to light. Using mechanical and optical band structure calculations, you will design, make, and measure phononic and photonic cavities. The project involves nanofabrication in the cleanroom, as well as using the extreme sensitivity offered by on-chip optomechanics. We are aiming for devices made from silicon nitride, which has a lot of tensile stress in it. For micromechanical structures this material gives much better mechanical properties compared to, for example, silicon devices. An important aspect of the project is to understand if this is also true for the high frequency devices.
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Imaging magnetic phases in 2D-materials |
Finley |
- Research group
- Semiconductor Nanostructures and Quantum Systems
- Description
The field of van der Waals heterostructures, which are stacks on individual atomically thin crystal sheets, has exploded in the last decade. Comparable to a game of Nano- Lego, those van der Waals stacks can be assembled in such a way that yield electro-optical nano-devices with essentially unlimited functionalities. Further, clever stacking can also result in new, fundamental physics.
The principal goal of this Masters thesis is to image magnetic phases of novel 2D-materials with a nitrogen-vacancy-based quantum camera system.
During the project, you will work in close collaboration with a small team of Ph.D.
students and postdocs, therefore individual effort is key to drive this Masters's project.
Some knowledge in the areas of van der Waals stacking, optics or cleanroom fabrication will be beneficial, but secondary to your personal motivation and commitment to this project.
You should:
(1) Be highly motivated and self-driven, (2) be practically minded with a get-things-done attitude, (3) enjoy working across a wide range of tasks (processing, optics, electronics) and (4) be willing to work in a very small team on challenging things very long hours ...
You will get:
(1) the chance to work on current hot-topic issues in the area of 2D van der Waals physics (2) gain highly sought after abilities in the field of quantum technologies (3) a sound understanding of the physics in atomically thin materials and hopefully (4) a few nice papers.
- Contact person
- Andreas Stier
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Kalibrierung von Frequenz und Nichtlinearität in einem Bose-Hubbard-System |
Gross |
- Research group
- Technical Physics
- Description
-
Bose-Hubbard systems offer an intriguing opportunity of studying quantum driven-dissipative dynamics. Nowadays, these systems can be conveniently implemented by combining superconducting resonators with Josephson junctions. In order to successfully measure nonclassical effects in these systems, such as generation of antibunched light, one needs to accurately quantify their respective frequency range and nonlinearity strength. This goal can be achieved by cryogenic microwave measurements of a Bose-Hubbard dimer with superconducting quantum circuits and numerical modelling of the respective Hamiltonian. These two steps comprise the main body of the current master project. The successful project will potentially lead to a development of robust single-photon microwave sources and further exploration of quantum matter in the form of networks of nonlinear superconducting resonators.
- Contact person
- Frank Deppe
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Kernspintomografie auf der Mikrometer-Skala (topic is not available any more) |
Reinhard |
- Research group
- Semiconductor Nanostructures and Quantum Systems
- Description
Magnetic resonance imaging (NMR/MRI), is one of the most powerful techniques to record three-dimensional images of nearly arbitrary samples. Current devices, such as those found in hospitals, cannot record details smaller than 1mm.
Our group aims to push MRI to a microscopy technique by improving its spatial resolution down to the sub-nm range, the scale of single atoms. This ambitious goal has recently become a realistic prospect by a new generation of quantum sensors for magnetic fields. They are based on the nitrogen-vacancy (NV) color defect in diamond and could detect fields as small as the NMR signal of a single molecule [1,2].
We are looking for a MSc student to develop a slightly different application: chip-scale NMR spectrometers for magnetic resonance imaging with a spatial resolution in the micrometer range.
Techniques:
* You will learn to fabricate microscale electromagnets in one of our clean rooms, and optimize our fabrication techniques for your project and others.
* You will design and fabricate a sensor chip for nanoscale magnetic resonance imaging
* You will redesign an existing microscope setup to apply strong magnetic fields and perform advanced imaging
* You will perform experiments to record microscale MRI images.
[1] T. Staudacher et al., Science 339, 561 (2013)
[2] H.J. Mamin et al., Science 339, 557 (2013)
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Langlebiger supraleitender Quantenspeicher in Hufeisengeometrie |
Deppe |
- Research group
- Technical Physics
- Description
| Long-lived and easy-to-address quantum memories are essential elements in quantum computing and quantum communication. At the WMI, we have recently built such a device in a compact form by placing a superconducting transmon qubit inside a high-quality 3D cavity resonator (E. Xie et al., Appl. Phys. Lett. 112, 202601, 2018, https://arxiv.org/abs/1803.04711). In addition, we have started to investigate potentialy advantageous cavity geometries. In your thesis, you investigate and improve the memory life time based such a novel cavity design and attempt optimal control strategies for improved memory process fidelities. |
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Optomechanics with Single Photons |
Poot |
- Research group
- Quantum Technologies
- Description
In optomechanics, light is used to measure and alter the dynamics of mechanical resonators. It is by far the most sensitive method to observe the tiny vibrations that nanomechanical devices perform: in one second one can determine their position with femtometer precision! Using light to measure the mechanics is not the only aspect of optomechanics. The same light can also be used to change the dynamics of the mechanical device through a process called cavity backaction. The photons exert a force on the resonator, the so-called radiation pressure. In this project we want to explore the ultimate limits to this force. The goal is to measure the force originating from a single photon! For this it is required that the photon interacts with the mechanical resonator as strongly as possible. For this we need to the design and make very low loss optical cavities, such as microring resonators. Also, the mechanical device should have a quality factor as high as possible. You will make both the optical and mechanical components from chips with highly-stressed silicon nitride using state-of-the-art nanofabrication in the cleanroom. Then the devices are placed in a vacuum chamber for their measurement. In our highly-automated setup you can very quickly characterize many of the devices on your chip. Then, with the perfect device parameters you can start to explore the more advanced measurements. Initially we can measure the devices in with pulsed light, but by using single photons we want to explore the ultimate limits to optomechanical forces.
See http://www.groups.ph.tum.de/en/qtech/openings/ for a detailed description of this project.
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Oxidische Heterostrukturen für Experimente mit reinen Spinströmen (topic is not available any more) |
Gross |
- Research group
- Technical Physics
- Description
Pure spin currents are generated and/or detected via the spin Hall and inverse spin Hall effect in heavy metals. These two effects crucially depend on the magnitude of the spin-orbit interaction. The goal of this thesis is to investigate the spin Hall physics in oxide systems, where large spin orbit interaction is prevailing like in the transition metal oxides. In particular, the realization of epitaxial multilayers of a spin Hall active material and a magnetically ordered insulator are a major task of this research project. Such all-oxide epitaxial structures are of current interest to better understand the underlying physics of pure spin current transport in heterostructures.
We are looking for an enthusiastic master student to work on this pure spin current physics related project. A crucial part of the thesis is the growth of oxide multilayers using laser-MBE under in-situ growth monitoring. The properties of these multilayers will then be investigated by structural, magnetic and magnetotransport techniques. As a next step, the tunability of relevant spin transport properties via the growth conditions will be analyzed - Contact person
- Stephan Geprägs
- Matthias Opel
- Matthias Althammer
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Qualifizierung von Piezo Motoren by kryogenen Temperaturen für das MADMAX Experiment zur Suche nach dunkle Materie Axionen |
Majorovits |
- Research group
- Max-Planck-Institute for Physics / Werner-Heisenberg-Institute (MPP)
- Description
Für den Betrieb des MADMAX Experimentes wurden Piezo Motoren entwickelt, die bei kryogenen Temperaturen (4 K) funktionieren und einen Hub von bis zu 1 m haben. Die ersten gelieferten Prototypmotoren müssen bei kryogenen Temperaturen getestet und auf verschiedene Betriebsparameter untersucht werden. Qualification of Piezo motors at cryogenic temperatures for the MADMAX axion dark matter experiment In the context of the MADMAX dark matter axion search experiment Piezo motors have been developed for operation at cryogenic temperatures (4 K) for a stroke of up to 1 m. The first prototype motors that have been delivered will need to be tested at cyrogenic temperatures and several parameters need to be investigated.
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Quantum Optics on a Chip |
Poot |
- Research group
- Quantum Technologies
- Description
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.
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Simulation und Aufbau einer Überhöhungskavität für hohe optische Leistungen |
Kienberger |
- Research group
- Laser and X-Ray Physics
- Description
- (English see below)
Hast Du Dich schon mal gefragt, was passieren würde, wenn man einen Lichtpuls zwischen zwei Spiegeln einfängt? Genau das wollen wir versuchen und damit die Grenzen der Physik im Bereich der hohen Laserleistungen ausloten. Ziel des Projektes ist eine Verbesserung von MuCLS, einer kompakten, aber brillanten Lichtquelle. Diese liefert Röntgenpulse durch inverse Comptonstreuung von Elektronen an Laserpulsen. Um die Intensität, die Wellenlänge und allgemeine Einsatzmöglichkeiten der Lichtquelle zu erweitern, beschäftigen wir uns mit einem Upgrade der Überhöhungskavität.
Aktuell sind wir dabei das Design des experimentellen Aufbaus zu finalisieren. Deine Aufgabe wird es sein, mit uns das Konzept umzusetzen. Das beinhaltet das Setup aufzubauen und zu testen. Gleichzeitig werden Simulationen durchgeführt werden, zum Beispiel um den Einfluss der Krümmungsradien der Spiegel besser zu verstehen. Die Ergebnisse werden direkt auf die Verbesserung des Aufbaus übertragen. Schlussendlich erhoffen wir uns das erste Mal eine Finesse von 30.000 in der grünen Überhöhungskavität zeigen zu können.
Alles Weitere erfährst Du bei einem persönlichen Gespräch.
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Have you ever asked yourself what would happen if you trap a pulse of light in between two mirrors? This is exactly what we are planning to do and thereby determine the boundaries of high-power laserphysics. The project as a whole is embedded in the frame of MuCLS, a compact but brilliant light source. This light source generates X-ray pulses by inverse Compton scattering of electron on a laser pulse. Upgrading the intensity, wavelength and overall quality of the laser pulse is the goal here in order to extend the range of applications.
Currently, we are finalizing the design of the overall experimental setup. Your task would be to support us in transforming the concept into reality. This includes building the setup and testing it. Meanwhile some simulations on different parameters such as the radius of curvature of the mirrors will have to be performed. The results will directly influence and improve the setup. In the end, we hope to show a finesse of 30.000 in the laser cavity.
If you are interested, feel free to get in touch.
- Contact person
- Albert Schletter
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Spectroscopy on atomically thin materials in high pulsed magnetic fields |
Finley |
- Research group
- Semiconductor Nanostructures and Quantum Systems
- Description
The field of van der Waals heterostructures, which are stacks on individual atomically thin crystal sheets, has exploded in the last decade. Comparable to a game of Nano-Lego, those van der Waals stacks can be assembled in such a way that yield electro-optical nano-devices with essentially unlimited functionalities. Further, clever stacking can also result in new, fundamental physics.
The principal goal of this Masters's thesis is to study the optical properties of actively tunable van der Waals heterostructures to examine topics such as exciton localization, many-body physics, exciton- exciton interactions, or the impact of complex dielectric environments on exciton properties in high to ultra-high magnetic fields.
  
During the project you will work in close
collaboration with a small team of Ph.D. students
and postdocs, therefore individual effort is key to drive this Masters's project.
Some knowledge in the areas of van der Waals stacking, optics, or cleanroom fabrication will be beneficial, but secondary to your personal motivation and commitment to this project.
You should:
(1) Be highly motivated and self-driven, (2) be practically minded with a get-things-done attitude, (3) enjoy working across a wide range of tasks (processing, optics), and (4) be willing to work in a very small team on challenging things very long hours ...
You will get:
(1) the chance to work on current hot-topic issues in the area of 2D van der Waals physics (2) exposure to experiments in large scale magnetic field facilities (3) a sound understanding of the physics in atomically thin materials and hopefully (4) a few nice papers.
- Contact person
- Andreas Stier
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Spin-dynamics in magnetic 2D-materials |
Finley |
- Research group
- Semiconductor Nanostructures and Quantum Systems
- Description
The field of van der Waals heterostructures, which are stacks on individual atomically thin crystal sheets, has exploded in the last decade. Specifically, magnetic 2D materials or heterostructures between different 2D materials have shown great promise for future information technology.
The principal goal of this Masters's thesis is to (i) enhance a currently available quantum camera system to enable coherent spin control of atomically thin materials (ii) image the spin lifetime and coherence times of magnetic phases of novel 2D-materials.
During the project you will work in close collaboration with a small team of Ph.D. students and postdocs, therefore individual effort is key to drive this Masters's project.
Some knowledge in the areas of van der Waals stacking, optics, electronics, or cleanroom fabrication will be beneficial, but secondary to your personal motivation and commitment to this project.
You should:
(1) Be highly motivated and self-driven, (2) be practically minded with a get-things-done attitude, (3) enjoy working across a wide range of tasks (processing, optics, electronics), and (4) be willing to work in a very small team on challenging things very long hours ...
You will get:
(1) the chance to work on current hot-topic issues in the area of 2D magnetism (2) gain highly sought after abilities in the field of quantum technologies (3) a sound understanding of the physics in atomically thin materials and hopefully (4) a few nice papers.
- Contact person
- Andreas Stier
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Strong electrostatic effects in optomechanical devices |
Poot |
- Research group
- Quantum Technologies
- Description
Optomechanics provides extremely sensitive methods to measure the displacement of mechanical resonators. However, the forces are much smaller in optomechanics compared to those in nanoelectromechanical systems (NEMS). The goal of the project is to make, and measure opto-electromechanical devices which have strong electrostatic interactions. This includes the electrostatic spring effect where the resonance frequency depends strongly on the applied voltage. The next step is trying to measure the potential by measuring the ringdown of different mechanical modes. The devices will be made using advanced nanofabrication techniques such as electron beam lithography and reactive ion etching.
See http://www.groups.ph.tum.de/en/qtech/openings/ for a detailed description of this project.
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Study of the electromagnetically induced transparency in the rare-earth spin ensembles in the microwave regime |
Gross |
- Research group
- Technical Physics
- Description
- A reliable quantum memory system is being actively searched for among different types of solid-state systems. In particular, rare-earth doped spin ensembles, which possess favorable transitions in optical and microwave ranges, are promising candidates. The current project aims at developing a quantum
memory system based on rare-earth spin ensembles. Such quantum memory elements should work at zero magnetic field at ultra-low temperatures. The major task of this project is to implement the electromagnetically induced transparency, widely used in optics, into the microwave regime.
We are looking for a highly motivated master student joining this project. Within your thesis, you will couple the spin-ensembles to the superconducting transmission lines and will manipulate the spin-states with microwave pulses. You will learn about the nature of the electromagnetically induced transparency and its application in quantum memory. Within the project, you will get hands on experience in synthesizing microwave pulses; how to measure the time responses of the spin-systems and how to operate such systems at cryogenic temperatures.
- Contact person
- Nadezhda Kukharchyk
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Time-domain study of the dynamics of microwave spectral holes in the rare-earth spin ensembles |
Gross |
- Research group
- Technical Physics
- Description
- A reliable quantum memory system is being actively searched for among different types of solid-state systems. In particular, rare-earth doped spin ensembles, which possess favorable transitions in optical and microwave ranges, are promising candidates. The current project aims at developing a quantum memory system based on rare-earth spin ensembles. Such quantum memory elements should work at zero magnetic field at ultra-low temperatures. The major task of this project is to implement the spectral hole burning technique, widely used in optics, into the microwave regime.
We are looking for a highly motivated master student joining this project. Within your thesis, you will address questions regarding the dynamics of spectral holes in the absorption profiles of the rare-earth spin ensembles in the microwave regime. You will couple the spin-ensembles to the superconducting transmission lines and will manipulate the spin-states with microwave pulses. Within the project, you will learn about dynamics of the spin-states, how to synthesize microwave pulses, measure the time responses of the spin-systems and how to operate such systems at cryogenic temperatures.
- Contact person
- Nadezhda Kukharchyk
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Tunable interlayer excitons in 2D heterostructures |
Finley |
- Research group
- Semiconductor Nanostructures and Quantum Systems
- Description
The field of van der Waals heterostructures, which are stacks on individual atomically thin crystal sheets, has exploded in the last decade. Specifically, heterostructures between different 2D materials have shown the emergence of interlayer excitons, due to the separation of charges at the interface. Furthermore, a lateral potential landscape, the so-called moiré potential, emerges, trapping the excitons in an egg-box shaped potential. This results in a situation where a few interlayer excitons can interact with each other, resulting in novel quantum phases.
The principal goal of this Masters's thesis is to study the optical properties of actively strain-tunable van der Waals heterostructures to examine topics such as exciton localization, many-body physics, exciton-exciton interactions in relation to the in-plane moiré potential.
During the project you will work in close collaboration with a small team of Ph.D. students and postdocs, therefore individual effort is key to drive this Masters's project.
Some knowledge in the areas of van der Waals stacking, optics, electronics, data analysis, or cleanroom fabrication will be beneficial, but secondary to your personal motivation.
You should:
(1) Be highly motivated and self-driven, (2) be practically minded with a get-things-done attitude, (3) enjoy working across a wide range of tasks (processing, optics, electronics) and (4) be willing to work in a very small team on challenging things very long hours ...
You will get:
(1) the chance to work on current hot-topic issues in the area of van der Waals heterostructures (2) gain highly sought after abilities in the field of 2D materials (3) a sound understanding of the physics in atomically thin materials and hopefully (4) a few nice papers.
- Contact person
- Andreas Stier
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Untersuchung der Signalantwort des MADMAX Experiments zur Suche nach Axionen als dunkler Materie |
Majorovits |
- Research group
- Max-Planck-Institute for Physics / Werner-Heisenberg-Institute (MPP)
- Description
Im Rahmen des MADMAX Projektes zur Suche nach dunkler Materie Axionen werden verschiedene
Testaufbauten bei Raumtemperatur und in flüssigem Helium (4 K)
zur Kalibrierung und zur Untersuchung der genauen Signalantwort des
experimentellen Aufbaus betrieben. Es werden Reflektionsdaten Daten
genommen und ausgewertet.
In the frame work of the MADMAX projects several test stands at room tamperature and in liquid helium
for the investigation of the detailled system response and for calibration of the setup are being operated. Reflectivity data will be atken and analyzed.
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Vermessung der optischen Eigenschaften des PEN-Szintillatormaterials für LEGEND200 |
Majorovits |
- Research group
- Max-Planck-Institute for Physics / Werner-Heisenberg-Institute (MPP)
- Description
PEN ist ein industriell hergestelltes Plastikmaterial, das das Interesse als Szintillator für Experimente der Teilchenphysik auf sich gezogen hat. PEN szintilliert im blauen Regime, ideal für viele Photosensoren. Zusätzlich hat PEN exzellente mechanische Eigenschaften. Ausserdem konnte eine sehr extrem niedrige Belastung surch natürliche Radiositope nachgewiesen werden. Dies macht PEN als strukturelles, szintillierendes Material für Experimente zur Suche nach extrem seltenen Ereignissen interessant. In diesem Zusammenhang wurden PEN Platten für das LEGEND200 Experiment zur Suche nach neutrinolosem Doppelbetazerfall hergestellt. Im Rahmen dieser Arbeit sollen die optischen Eigenschaften diser Platten vermessen werden. Es sollen verschiedene PEN Samples mit einem existierenden Messaufbau auf Emissions- und Absorbtionsspektrum, sowie Lichtausbeute und Attenuierungslänge untersucht werden.
PEN is an industrial plastic that has drawn the interest as a new type of plastic scintillator material. PEN scintillates in the blue regime, which is ideal for most photosensor devices. In addition, PEN has excellent mechanical properties and very good radiopurity has been achieved, which makes it an ideal candidate as an active structural scintillator material in low-background physics experiments. In this context, PEN plates have been produced for use in the LEGEND200 experiment for the search of neutrinoless double beta decay. The goal of this thesis will be the measurement of the main optical properties of PEN. The emission and absorption spectrum, attenuation length, and light output will be measured for several PEN samples using existing setups.
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