Theory projects

 

Unsolicited applications

In addition to the advertised projects, we are always happy about unsolicited applications. Please contact the principal investigator with whom you'd like to work with to discuss possible projects.

  Damped harmonic oscillator Copyright: Lisa Arndt

B.Sc. Project Radiation of the harmonic oscillator

In this project, you will analyse and simulate a quantum harmonic oscillator that is coupled to external modes, e.g., a LC-resonator coupled to a transmission line. The coupling can annihilate excitations in the harmonic oscillator by moving the energy in the transmission line where it appears as radiation. This effectively leads to dissipation. By employing various methods, you will study the time-evolution of the system. Another important research topic is to characterize the radiation that is emitted in the external mode.
Contacts: , Fabian Hassler

  Shapiro setup Copyright: Lisa Arndt

B.Sc. Project Quantum noise and dual Shapiro steps

In this thesis, you will explore the influence of quantum noise on the height of the dual Shapiro steps. You will start by simulating a classical system of a driven phase-slip junction in the presence of dissipation. Next, you will add quantum noise to the classical Langevin equation and analyse how the additional noise influences the height of the dual Shapiro steps.
Contacts: , Fabian Hassler

  Detector setup Copyright: Fabian Hassler

M.Sc. Project Detector theory for microwave photonics with superconducting quantum circuits

In superconducting quantum systems, a significant part of the emitted microwave radiation can be collected and converted to an amplified output signal. This allows for a detailed study of the correlations of the radiation. The statistics of the radiation can offer a valuable insight into the quantum nature of the radiation. It demonstrates phenomena like squeezing or multi-photon processes. In order to study such phenomena theoretically, it is necessary to develop a fitting model for the detector. The goal of this project will be to explore different theoretical detector models for microwave photonics, including the initial detection of the photons, the amplification of the signal, and possible backaction due to the detector.
Contacts: , Fabian Hassler

  Hall bar Copyright: David DiVincenzo

B.Sc. Project

Hall Effect Gyrator

This work will continue recent investigations in our group on the action of an essential component in quantum microwave science, the gyrator. Here you will do calculations of the real-time propagation of electromagnetic fields in this device. Contact: David DiVincenzo

  Qubit-Heterostructure Copyright: Pascal Cerfontaine

B.Sc. Project Improved Quantum Dot Qubits

In this project you will explore theoretically variants of the semiconductor quantum dot to perform quantum gate fidelity and readout. There will be an emphasis on tailoring the spin-orbit action to achieve optimal performance, and on varying the electron number and confinement strength. Contact: David DiVincenzo

  Flux Qubit Copyright: Gianluigi Catelani

B.Sc. and M.Sc. Projects Superconducting Qubits

In these projects you will study theoretically some basic properties (energy levels, wave functions, matrix elements) of superconducting qubits such as the fluxonium and the flux qubit. These properties can be accurately calculated numerically in most cases, especially if the problem reduces to that of a quantum particle in a one-dimensional potential. The goal here is to construct an approximate but accurate analytical solution to such a quantum-mechanical problem, using perturbation theory, the WKB approximation, etc. For a B.Sc. project, a symmetric double-well potential will be analyzed. Extension of the results to asymmetric potentials, and to two- or three-dimensional problems, can be considered for a M.Sc. project. Contact: Gianluigi Catelani (g.catelani@fz-juelich.de)