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Prof. Dr. Rudolf Gross

Photo von Prof. Dr. rer. nat. habil. Rudolf Gross.
Phone
+49 89 289-14201
Room
E-Mail
rudolf.gross@tum.de
Links
Homepage
Page in TUMonline
Group
Technical Physics
Job Title
Professorship on Technical Physics
Consultation Hour
on appointment

Courses and Dates

Title and Module Assignment
ArtSWSLecturer(s)Dates
Condensed Matter Physics 2
Assigned to modules:
VO 4 Gross, R. Tue, 12:00–14:00, PH HS2
Tue, 08:30–10:00, PH HS2
Mon, 12:15–14:00, PH HS2
Mon, 10:00–11:30, PH HS2
Exercise to Condensed Matter Physics 2
Assigned to modules:
UE 2
Responsible/Coordination: Gross, R.
dates in groups
Colloquium on Solid State Physics
current information
Assigned to modules:
KO 2 Gross, R. Thu, 17:00–19:00, PH HS3

Offered Bachelor’s or Master’s Theses Topics

Breitbandiges dispersives Auslesen von supraleitenden Qubits

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.

suitable as
  • Master’s Thesis Condensed Matter Physics
  • Master’s Thesis Applied and Engineering Physics
  • Master’s Thesis Quantum Science & Technology
Supervisor: Rudolf Gross
Elektronenspindynamik in einer stark koppelnden Umgebung

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

suitable as
  • Master’s Thesis Condensed Matter Physics
  • Master’s Thesis Applied and Engineering Physics
  • Master’s Thesis Quantum Science & Technology
Supervisor: Hans Hübl
FPGA-basiertes Rückkopplungsverfahren für die Mikrowellen-basierte Quantenkommunikation

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.

suitable as
  • Master’s Thesis Condensed Matter Physics
  • Master’s Thesis Applied and Engineering Physics
  • Master’s Thesis Quantum Science & Technology
Supervisor: Rudolf Gross
High-field magnetotransport in an organic superconductor in proximity to the spin-liquid state

A member of the k-(ET)2X family to be studied in this Master thesis exhibits 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 conducting system, particularly, of correlation effects, in close proximity to the superconductor-insulator phase boundary. The intrinsic properties of charge carriers will be probed by high-field magnetoresistance effects with the focus on magnetic quantum oscillations. A part of the experiments will be done at the European Magnetic Field Laboratory in steady fields up to 30 T or in pulsed fields up to 80 T.

Physics: Correlated electron systems; 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

suitable as
  • Master’s Thesis Condensed Matter Physics
  • Master’s Thesis Applied and Engineering Physics
Supervisor: Rudolf Gross
Interaction between magnetic and conducting layers in molecular antiferromagnetic superconductors

Hybrid materials combining nontrivial conducting and magnetic properties are of high current interest, especially in the context of potential spintronic applications. The organic charge transfer salts (BETS)2FeX4 with X = Cl, Br provide perfect natural structures of conducting and magnetic layers alternating on the single-molecule level. Our project is aimed at a quantitative study of the interaction between the two subsystems and of the role of the subtle structural modifications in this family. To this end, high-precision measurements of quantum oscillations in the electrical resistance and magnetization will be carried out on single crystals of these compounds under strong magnetic fields. The results will be analyzed in terms of electronic correlation and magnetic interaction effects.

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)

suitable as
  • Master’s Thesis Condensed Matter Physics
  • Master’s Thesis Applied and Engineering Physics
Supervisor: Rudolf Gross
Kalibrierung von Frequenz und Nichtlinearität in einem Bose-Hubbard-System

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.

suitable as
  • Master’s Thesis Condensed Matter Physics
  • Master’s Thesis Applied and Engineering Physics
  • Master’s Thesis Quantum Science & Technology
Supervisor: Rudolf Gross
Magnetization dynamics in chiral magnets

Chiral magnetic materials show exotic magnetic properties such as a skyrmion lattice phase and have strong application potential for future spintronic devices. For these applications, a detailed understanding of the magnetization dynamics in these materials is required. At WMI, we routinely use broadband magnetic resonance spectroscopy to study magnetization dynamics as a function of magnetic field, temperature and frequency in a wide range of different materials. Now, magnetization dynamics in thin film and bulk chiral magnets shall be explored, with a focus on novel resonance phenomena.

We are looking for a highly motivated and talented master student who is interested in joining our magnetization dynamics project. During your thesis, you will use state-of-the-art microwave equipment such as vector network analyzers as well as magnet cryostats and will work on the forefront of a rapidly developing scientific field.

suitable as
  • Master’s Thesis Condensed Matter Physics
  • Master’s Thesis Applied and Engineering Physics
Supervisor: Rudolf Gross
Magnetomechanik mit freischwebenden Nanostrukturen

Nano-mechanical strings are archetypical harmonic oscillators and can be straightforwardly integrated with other nanoscale systems. For example, the field of nano-electromechanics studies the coupling of nano-strings to microwave circuits, which resulted in the creation of mechanical quantum states and concepts for microwave to optics conversion. Here, we plan to investigate an alternative hybrid system based on ferromagnetic nanostructures integrated with nano-strings or nano-mechanical platforms. These hybrid devices enable the design and the investigation of spin-phonon coupling down to the single excitation level and are expected to allow the investigation of the Einstein-de Haas on the nanoscale, where the angular momentum change arising from magnetization reversal is transferred into a mechanical vibration of the beam. In addition, these systems are key for the investigation of strong magnon-phonon coupling.

We are looking for a motivated master student for a nano-mechanical master thesis in the context of magnon-phonon interaction. The goal of your project is to investigate the static and dynamic interplay between the mechanical and magnetic properties of a nano-mechanical system sharing an interface with a magnetic layer. In your thesis project you will fabricate freely suspended nanostructures based on silicon nitride or silicon and deposit on them ferromagnetic multi layers using state-of-the-art nano-lithography and metal deposition techniques. Further, you will probe the mechanical response of the nano-structures using optical interferometry while exciting the magnetization dynamics of the magnetic system

suitable as
  • Master’s Thesis Condensed Matter Physics
  • Master’s Thesis Applied and Engineering Physics
  • Master’s Thesis Quantum Science & Technology
Supervisor: Hans Hübl
Manipulation von Spinwellen mit durch Spin-Bahn-Koppling vermittelten Drehmomenten

The field of magnonics deals with exploiting the collective spin dynamics (spin waves) of magnetically ordered materials for computational purposes. Efficient and scalable schemes for controlling spin waves in thin film ferromagnets thus have large application relevance. The magnetic torques arising due to the spin-orbit interaction allow to control spin waves by electric currents and acoustic waves at GHz frequencies. We are particularly interested in a spatially-resolved study of the interaction of spin waves with acoustic and current-induced torques in nanopatterned devices with application potential for spintronics.

We are looking for a talented and highly motivated master student who is interested in joining our spin dynamics project. During your thesis, you will use state-of-the-art nanolithography and thin film deposition tools to fabricate hybrid devices that allow for the interaction of spin waves with electrical currents and acoustic waves. You will study spin waves in these devices using optical and microwave spectroscopy methods

suitable as
  • Master’s Thesis Condensed Matter Physics
  • Master’s Thesis Applied and Engineering Physics
  • Master’s Thesis Quantum Science & Technology
Supervisor: Rudolf Gross
Nano-strings excited by magnetic torques

Nano-mechanical beams are prototype harmonic oscillators, and can be straightforwardly integrated with other nanoscale systems. For example, coupling nano-beams to coplanar microwave cavities yields so-called hybrid electro-mechanical systems with intriguing properties, e.g., electro-mechanically induced transparency. In a similar fashion, ferromagnetic nanostructures can be integrated with nano-beams. This enables the design and the investigation of spin-phonon coupling down to the single excitation level, or nanoscale Einstein-de Haas experiments, in which the angular momentum change arising from magnetization reversal is transferred into a mechanical vibration of the beam. 

We are looking for a motivated master student for a magnetic nano-beam oriented master thesis. The goal of your project is to investigate the static and dynamic interplay between the mechanical properties of double layer nano-beams and its magnetic properties. In your thesis project you will fabricate freely suspended nanostructures based on silicon nitride and ferromagnetic multi layers using state-of-the-art nano-lithography and metal deposition techniques. Further, you will probe the mechanical response of the nano-structures using optical interferometry while exciting the magnetization dynamics of the magnetic system. 

 
suitable as
  • Master’s Thesis Condensed Matter Physics
  • Master’s Thesis Applied and Engineering Physics
Supervisor: Rudolf Gross
Quanten-Illumination und -Sensorik mit Mikrowellen

Quantum microwaves emitted by superconducting circuits can be used for distributed quantum computation or improved quantum illumination/radar. You will join the Quantum Flagship activities on the latter, working towards the demonstration of a quantum advantage in a laboratory setting.


Keywords: Quantum microwaves, quantum communication, quantum illumination, quantum radar

suitable as
  • Master’s Thesis Condensed Matter Physics
  • Master’s Thesis Applied and Engineering Physics
  • Master’s Thesis Quantum Science & Technology
Supervisor: Frank Deppe
Spintransport in Supraleiter/Ferromagnet-Heterostrukturen

The combination of ferromagnetic and superconducting materials leads to intriguing proximity effects at the interface of the two materials. The goal of this thesis is to investigate the spin transport of superconductor/ferromagnet interfaces and model the obtained results in the framework of proximity effects. To this end, we will use broadband ferromagnetic resonance and magnetoresistance effects to inject a spin current into the superconductor. This requires investigations at low temperatures around the critical temperature of the superconductor in large magnetic fields. For the superconductor/ferromagnet magnetoresistance effects, the magnetic field orientation dependence and its influence on the Andreev reflection contribution is the focus of this study.

We are looking for a talented master student to investigate spin transport in superconductor/ferromagnet heterostructures. The thesis deals with the fabrication of these heterostructures using our new UHV sputtering system and structuring of the blanket films with optical and electron beam lithography. In addition, characterization of theses heterostructures at low temperatures will be conducted in superconducting magnet cryostats. Here, high frequency spin dynamics as well magnetotransport studies will be conducted

suitable as
  • Master’s Thesis Condensed Matter Physics
  • Master’s Thesis Applied and Engineering Physics
  • Master’s Thesis Quantum Science & Technology
Supervisor: Rudolf Gross
Steuerung des Magnonentransports

Magnon transport in magnetic insulators has similarities and differences compared to the familiar transport properties of their charge counterparts. For example, diffusive transport is a shared feature, while the obvious difference is that charges are a conserved quantity and magnons are excitations decaying with a characteristic lifetime. The aim of this thesis is to obtain a better understanding how to control the magnon transport in magnetic insulators (e.g. yttrium iron garnet). In particular, we plan to focus on heat driven magnon transport properties as well as the control of the magnon conductance by electrical means. Interesting transport observables in this context will be magnon resistivity as well as the investigation of magnon correlation length.

We are looking for a master student interested in magnon transport experiments. In order to answer questions regarding magnon transport in magnetic insulators, your thesis will contain aspects of the fabrication of nano-scale devices using electron beam lithography as well as ultra-sensitive low-noise electronic measurements in a cryogenic environment

suitable as
  • Master’s Thesis Condensed Matter Physics
  • Master’s Thesis Applied and Engineering Physics
  • Master’s Thesis Quantum Science & Technology
Supervisor: Rudolf Gross
Topologische magnetische Phasen in Dünnschicht-Heterostrukturen

The broken inversion symmetry at the interface of thin film ferromagnets and normal metals with strong spin-orbit coupling can give rise to chiral magnetic order. These chiral magnetic materials show exotic magnetic properties such as a skyrmion lattice phase and have strong application potential for future spintronic devices. For these applications, a detailed understanding of the magnetization dynamics in these materials is required. The goal of this master thesis is to fabricate such thin film multilayer structures using sputter deposition techniques and analyze their dynamic magnetic properties using broadband ferromagnetic resonance spectroscopy.

We are looking for a highly motivated master student to carry out these experiments on interfacial effects in metallic multilayers. In this thesis you will work on the fabrication of these multilayer structures using UHV sputter deposition systems and subsequently determine their magnetic properties using broadband ferromagnetic resonance spectroscopy and SQUID magnetometry

suitable as
  • Master’s Thesis Condensed Matter Physics
  • Master’s Thesis Applied and Engineering Physics
  • Master’s Thesis Quantum Science & Technology
Supervisor: Rudolf Gross
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