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Prof. Dr. Rudolf Gross

Photo von Prof. Dr. rer. nat. habil. Rudolf Gross.
Phone
+49 89 289-14249
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 1
course documents
Assigned to modules:
VO 4 Gross, R. Tue, 12:00–14:00, PH HS2
Thu, 10:00–12:00, PH HS2
Superconductivity and Low Temperature Physics 1
eLearning course course documents
Assigned to modules:
VO 2 Hackl, R.
Responsible/Coordination: Gross, R.
Thu, 12:00–14:00, PH HS3
Advances in Solid State Physics
course documents
Assigned to modules:
PS 2 Gross, R. Tue, 10:15–11:30, WMI 143
Superconducting Quantum Circuits
course documents
Assigned to modules:
PS 2 Deppe, F.
Responsible/Coordination: Gross, R.
Assisstants: Fedorov, K.Marx, A.
Tue, 14:30–16:00, WMI 142
Exercise to Condensed Matter Physics 1
course documents
Assigned to modules:
UE 2 Geprägs, S.
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
FOPRA Experiment 16: Josephson Effects in Superconductors
current information
Assigned to modules:
PR 1 Gross, R.
Assisstants: Chen, Q.Nojiri, Y.Rager, G.Wimmer, T.
Revision Course to Advances in Solid State Physics
Assigned to modules:
RE 2
Responsible/Coordination: Gross, R.
Revision Course to Superconducting Quantum Circuits
Assigned to modules:
RE 2
Responsible/Coordination: Gross, R.
Walther-Meißner-Seminar on Topical Problems of Low Temperature Physics
current information
Assigned to modules:
SE 2 Gross, R. Fri, 13:30–14:45, WMI 143

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
Controlling magnon transport in antiferromagnetic insulators
In antiferromagnetic insulators, we obtain two magnon modes with opposite spin chirality due to the two opposing magnetic sublattices. In this way, magnon transport in antiferromagnetic insulators can be considered as the magnonic equivalent of spin transport via electrons. The aim of this thesis is to obtain a better understanding of the magnon transport in antiferromagnetic insulators and investigate external control parameters that allow a manipulation of the spin information transport in the antiferromagnetic insulator. Moreover, these experiments allow to extract important transport properties like for example the magnon spin life-time. We are looking for resourceful master student heavily interested in these 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
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
Quantum acoustics in novel piezoelectric multi-layer systems
The field of quantum acoustics aims to investigate quantum mechanical effects in acoustic resonator structures. Combined with e.g. optical and / or superconducting circuits, this offers the possibility to create quantum hybrid systems, which are discussed in the context of storing and converting quantum states. In this project, we shall investigate one of the building blocks, i.e. the surface acoustic wave (SAW) resonator. With your help, we aim to develop and optimize SAW resonators operating in the GHz frequency range with high quality factors and test these devices at moderately low (3-10K) and millikelvin temperatures. Your bachelor thesis will bring you in touch with state-of-the-art nanofabrication technology and introduce you to microwave spectroscopy tools like vector network analyzers, as well as cryogenic measurement environments. Careful data analysis of the transmission and reflection data of these resonators combined with modeling will put you in the position, to make a meaningful contribution to the creation of quantum hybrid systems.
suitable as
  • Bachelor’s Thesis Physics
Supervisor: Hans-Gregor Hübl
Quantum acoustics in the giant atom limit
The field of quantum acoustics aims to investigate the interaction between matter and sound, in a similar way that quantum optics (QO) studies the interaction between matter and light. In detail, we enable this interaction using surface acoustic waves (SAWs) and artificial atoms (Qubits) formed by superconducting quantum circuits. Quantum acoustics offer interesting differences to quantum optics. The propagation speed of sound in solids is approximately five orders of magnitude slower than for light in vacuum, leading to the SAWs much shorter wavelengths compared to electromagnetic waves. This allows the exploration of the “giant atom” regime in which the size of the artificial atoms becomes comparable to or larger than the wavelength of the interacting wave. In this regime, interesting physics like interference and non-exponential decay of quantum states become accessible. We are looking for a motivated master student for a master thesis in the context of quantum acoustics. The goal of your project is to investigate the static and dynamic interplay between surface acoustic waves and one (or more) superconducting qubits. Your thesis project includes the fabrication of aluminium-based superconducting circuits on silicon and lithium niobate using state-of-the-art nano-lithography and metal deposition techniques. Subsequently, these circuits shall be experimentally investigated in a cryogenic microwave measurement setup. As such, the project will allow you to gather expertise in quantum physics, nanofabrication, microwave engineering, and cryogenic techniques.
suitable as
  • Master’s Thesis Condensed Matter Physics
  • Master’s Thesis Applied and Engineering Physics
  • Master’s Thesis Quantum Science & Technology
Supervisor: Hans-Gregor Hübl
Study of the electromagnetically induced transparency in the rare-earth spin ensembles in the microwave regime
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.
suitable as
  • Master’s Thesis Condensed Matter Physics
  • Master’s Thesis Applied and Engineering Physics
  • Master’s Thesis Quantum Science & Technology
Supervisor: Rudolf Gross
Superconducting devices based on superconductor/ferromagnet heterostructures
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 fabricate superconducting devices based on superconductor/ferromagent heterostructures with a special focus on controlling magnetization dynamics via superconducting charge currents. This requires investigations at low temperatures around the critical temperature of the superconductor in large magnetic fields. In addition microwave magnetic fields will be employed to drive magnetization dynamics in the ferromagnet and excitations in the superconductor. We are looking for a talented master student to investigate spin transport in superconductor/ferromagnet heterostructures. You will fabricate superconductor/ferromagnet heterostructures using our new UHV sputtering system. As a next step, you will structure these blanket films with optical and electron beam lithography into superconducting devices. Finally, you will characterize your fabricated samples at low temperatures utilizing superconducting magnet cryostats. Here, high frequency spin dynamics as well magnetotransport studies are the focus of your thesis.
suitable as
  • Master’s Thesis Condensed Matter Physics
  • Master’s Thesis Applied and Engineering Physics
Supervisor: Rudolf Gross
Superconducting spintronics with magnetic insulators

Combining the fields of superconductivity and spintronics can lead to novel functionalities, which mainly arise at the interface of a superconductor and a magnetic material. For example, proximity to a magnetic insulator induces superconductivity with Cooper pair spin triplets. You will be advancing this field by preparing thin film heterostructures of superconductors and magnetic insulators. In addition, within your thesis you will investigate the magnetotransport properties of these heterostructures at low temperatures.

You will work with state-of-the-art thin film deposition machines to carry out this task. Moreover, you will utilize nanolithography for structuring your samples. Furthermore, you will utilize low temperature setups and low noise measurement techniques to gain insight into the interface effects arising at the superconductor/magnetic material interface. 

suitable as
  • Bachelor’s Thesis Physics
Supervisor: Rudolf Gross
Tailoring magnon transport in magnetic insulators
By reducing the dimension of materials we can enter into the world of novel quantum classes of materials. Especially, in the limit of 1-dimensional transport, fascinating phenomena like the quantization of transport properties are observed. With your Bachelor thesis you will advance our magnon transport experiments in thin film magnetic insulators by further reducing the lateral dimensions of the magnon transport channel. Utilizing scanning probe microscopy, you will analyze the surface topography of the structured devices, magnetic properties and optimize the fabrication processes. You will utilize sophisticated nano-lithography in combination with state-of-the-art thin film deposition techniques to constrain the magnon transport channel in magnetic insulators. In addition, you will gain insight into scanning probe microscopy, one of the frontrunners for surface spectroscopy analysis.
suitable as
  • Bachelor’s Thesis Physics
Supervisor: Hans-Gregor Hübl
Time-domain study of the dynamics of microwave spectral holes in the rare-earth spin ensembles
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.
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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