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Prof. Dr. techn. Stefan Filipp

Photo von Prof. Dr. techn. Stefan Filipp.
Phone
+49 89 289-14201
Room
E-Mail
stefan.filipp@tum.de
Links
Homepage
Page in TUMonline
Group
Technical Physics
Job Title
Professorship on Technical Physics

Courses and Dates

Title and Module Assignment
ArtSWSLecturer(s)Dates
Quantum Computing with Superconducting Qubits: architecture and algorithms
eLearning course
Assigned to modules:
VO 2 Filipp, S. Mon, 14:00–16:00, WMI 143
Quantum Entrepreneurship Laboratory
Assigned to modules:
HS 2 Filipp, S. Mendl, C. Pollmann, F.
Superconducting Quantum Circuits
course documents virtual lecture hall
Assigned to modules:
PS 2 Deppe, F. Filipp, S.
Responsible/Coordination: Gross, R.
Assisstants: Fedorov, K.Marx, A.
Tue, 14:30–16:00, WMI 142
Exercise to Quantum Computing with Superconducting Qubits: architecture and algorithms
eLearning course
Assigned to modules:
UE 2
Responsible/Coordination: Filipp, S.
dates in groups
Journal Club on Quantum Systems
Assigned to modules:
SE 2 Filipp, S. Tue, 14:30–16:00, virtuell
Revision Course to Quantum Entrepreneurship Laboratory
Assigned to modules:
RE 2
Responsible/Coordination: Filipp, S.
Walther-Meißner-Seminar on Topical Problems of Low Temperature Physics
current information
Assigned to modules:
SE 2 Filipp, S. Gross, R. Fri, 11:00–12:30, WMI 143

Offered Bachelor’s or Master’s Theses Topics

Dynamical decoupling and noise spectroscopy with superconducting qubits
The characterization and mitigation of decoherence sources in qubits is crucial for quantum computing applications. Decoherence of a quantum superposition state arises from the interaction between the system and the uncontrolled degrees of freedom in its environment. The qubit decoherence is characterized by two rates: a longitudinal relaxation rate Γ1 due to the exchange of energy with the environment, and a transverse relaxation rate Γ2 = Γ1/2 + Γϕ which contains the pure dephasing rate Γϕ. Irreversible energy relaxation can only be mitigated by reducing the amount of environmental noise, reducing the qubit’s internal sensitivity to that noise, or through multi-qubit encoding and error correction protocols. In contrast, dephasing is in principle reversible and can be refocused dynamically through the application of coherent control pulse methods. In this work we are going to investigate different sources of noise and decoherence and how dynamical-decoupling techniques such as CPMG can change the dephasing effects of low-frequency noise on a superconducting qubit.
suitable as
  • Bachelor’s Thesis Physics
Supervisor: Stefan Filipp
Improving qubit coherence times by surface engineering
Characterization of surfaces is currently a hot topic for the fabrication of superconducting quantum processors. One way to determine surface properties is the measurement of the contact angle of a deionized water droplet on the surface of differently fabricated chips. For this purpose a measurement setup will be built within this thesis. Afterwards the images will be analyzed using a software called "ImageJ" to extract the contact angle between the chipsurface and the droplet. To compare the results from contact angle measurements to qubit performance, qubit chips will be fabricated and measured at cryogenic temperatures.
suitable as
  • Bachelor’s Thesis Physics
Supervisor: Stefan Filipp
Non-reciprocal devices for microwave signal routing

Breaking time-reversal symmetry by external magnetic fields leads to non-reciprocal behavior of microwave propagation that can be used for signal routing and isolation. In the context of superconducting qubits this becomes relevant to shield the qubits from incoming radiation along the readout path.
 
In this project you will gain an understanding of different types of circulators and isolators and evaluate high bandwidth realizations based on Josephson junction elements or novel materials, in which chiral edge plasmons or topological insulators could be used for non-reciprocal devices without external fields. In collaboration with the group of Prof. Knolle and the group of Prof. Holleitner we will explore a variety of different materials both from the theoretical and the experimental perspective. You will then test suitable realizations at cryogenic temperatures, study losses and reflection properties and investigate, how these devices can be integrated directly onto the  superconducting qubit chip.

suitable as
  • Master’s Thesis Condensed Matter Physics
Supervisor: Stefan Filipp
Simulation and comparison of non-planar qubit architectures
Scalable designs of superconducting qubits are essential for the creation of large-scale multi-qubit processors used in quantum computers. Superconducting transmon qubits are described by their characteristic capacitance and the critical current of their Josephson-Junction. The capacitance of these qubits orginates from the geometry of the metal islands of the qubit on the chip surface. To accomodate for a large number of qubits and their respective control and readout lines new 3D integration methods have been developed over the last years, extending the superconducting structures beyond a single chip plane. In this work a number of these architectures will be simulated. The focus of this Bachelor thesis lies in the accurate simulation of these designs ranging over different orders of magnitude in size and the extraction of system paramerters from FEM solutions.
suitable as
  • Bachelor’s Thesis Physics
Supervisor: Stefan Filipp
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