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B.Sc./FP-Project
Supervisor: Jonathan Wischnat

Goal: Design and synthesis of organic radicals with photoactive moieties towards potentially switchable qubit systems. Examination of the magnetic and optical properties and structural variation to finetune the properties as necessary.

B.Sc./FP-Project
Supervisor: Alexander Allgaier

Goal: Spectroscopically characterization of chromium-based catalyst for oligomerization of ethylene under catalytic conditions. By that, the electronic structure of the inactive catalyst, and during catalysis, should be resolved.

B.Sc./M.Sc./FP-Project
Supervisor: Valentin Bayer

Goal: Development and/or characterization of new coordination compounds based on the stable Verdazyl radical for the potential use as a quantum bit.

B.Sc./FP-Project
Supervisor: Sally Eickmeier

Goal: Evaporation of organic molecules and analysis of the produced organic thin films.

B.Sc./M.Sc./FP-Project
Supervisor: Jake McGuire

Goal: Investigation of spin-electric coupling in highly-tunable molecular spin qubit architectures. The influence of spin-state, spin-orbit coupling, and delocalization and symmetry on spin-electric coupling.

Methods:

• Electrochemistry (cyclic voltammetry and EIS)
• Spectroelectrochemistry
• Cw X-band EPR Spectroscopy
• Cw spin-electric X-band EPR Spectroscopy
• Pulsed Q-band EPR
• Electronic Spectroscopy
• Simulation

Background:

Molecular quantum bits (MQBs) are promising candidates as the hardware of a quantum computer. As these devices are being physically realized with super-conducting bits or nitrogen-centered vacancies in diamond, the addressability of the quantum bits (qubits) poses a severe bottleneck, that is, the ability to write and read data to these qubits. Magnetic fields are intrinsically difficult to control and change in the precise regime required for operation of a quantum computer is incredibly limiting with current technology. In contrast, electric field generation and control is trivial. Paramagnetic molecules, with specific geometries among other conditions, can couple with electric fields, dubbed spin-electric coupling. However, this effect is conventionally quite weak. Using the high tunability of molecular systems we look to develop design principles to maximize spin-electric coupling, while preserving the properties required for MQBs; long coherence times.

It is known that spin-electric coupling is operative locally in paramagnetic molecules without inversion centers. N2S2 tetradentate fused bis(aminothiolate)s have been known since the 60s and exhibit coordination to a wide range of metals. They can, in some cases, undergo reduction to form radical ligands. A slight caveat is that their tunability has not been fully explored. In-group, some methodology has been developed towards customizing these to fully capitalize on this system.

Known transition metal complexes, such as those in figures 1 (Examples of fused bis(aminothiolate) complexes with varied symmetry and, therefore, electron distribution where M is Ni, Pd, or Pt) and 2 (A series of S,S′-ethyl-N,N′-benzyl-bis(benzeneaminothiolate) (ebbbat) complexes with varying spin state. [Cu(ebbbat)Cl₂], [Cr(ebbbat)Cl₂], and [Mn(ebbbat)Cl₂] with S = 1/2, 3/2, and 5/2 respectively), form convenient series to explore the influence of spin-orbit coupling or spin state. With these we look to fully investigate and characterize the magnetic and electronic properties of these complexes and further develop experimental methodology to investigate spin-electric coupling, which at present consists of connection of the sample between two electrodes and sweeping the field.

This project has wide scope and can be tailored to the interests of the student, whether that be measurement, synthesis, simulation, or development.

B.Sc./M.Sc./FP-Project
Supervisor: Radhika Kataria

Goal: Preparation and characterization of hybrid thin films of a semiconducting polymer and a molecular quantum bit as a platform for molecular spintronics.

Methods:

• Film preparation using spin-coating or drop-casting techniques
• Topographic and optical characterization using atomic force microscopy (AFM) and UV-Vis spectroscopy
• Organic Field-Effect Transistor (OFET) measurements for investigating the charge transport properties
• Continuous wave and pulsed Electron Spin Resonance (ESR) Spectroscopy for probing the static and dynamic spin properties

Background:

A quantum bit or a qubit forms the basic unit of almost all quantum technologies. Molecular qubits (MQBs), which are qubits based on electron spins in paramagnetic molecules, are interesting because of their chemical tunability and long coherence times. Integrating these qubits with semiconducting polymers provides a novel platform to access and exploit the spin information via electrical means. This approach can provide increased spin detection sensitivity and facile integration with electronic devices.

This bachelor’s/master’s thesis or research internship aims to introduce the student to the interdisciplinary and emerging fields of organic and molecular spintronics. The research will focus on depositing thin films of a semiconducting polymer and a molecular qubit on silicon or plastic substrates. These will then be characterized for their electrical and magnetic properties using spectroscopic and charge transport measurements. Emphasis will be on the optimization of parameters such as temperature and qubit concentration to retain the desired charge-transport and spin properties of the hybrid films.

Specific goals and tasks can be decided based on the interests of the student and the research level (B.Sc./FP/M.Sc.) and the duration of the project. For those interested, a component of synthesis could also be included.

B.Sc./M.Sc./FP-Project
Supervisor: Dominik Bloos

Goal: Synthesis and functionalization of the novel 2D-material graphdiyne for quantum electronics.

B.Sc./M.Sc./FP-Project
Supervisor: Lorenzo Tesi

Goal: Determine the influence of plasmonic structures on the resulting HF-EPR spectra for different magnetic samples.

Methods:

• Sample preparation includes spin-coating or dropcast approaches;
• Magnetic characterization of several different molecular systems by cw-EPR, HF-EPR and THz transmission measurements;
• Data analysis with Python, Origin or Matlab;
• Electromagnetic fields modelling with CST Studio software.

Background: 

The development of resonators for HF-EPR is limited by the EPR extreme frequency range used (sub-THz up to 1 THz). The structures we are designing increase the sensitivity of HFEPR technique, thus facilitating a wide range of applications. This is an innovative project that merges the research areas of plasmonics, metamaterials, THz frequencies and EPR. First results have confirmed what modelled by numerical simulations and now a broader investigation must be carried out on several new designed micro-antennas. It is a very interdisciplinary topic, for which chemists, physicist, engineers, and material sciences students are welcome.

Tasks:

Several types of studies can be performed depending on the interest of the student. The project can be more focused on the design and simulation or vice versa on the experimental side. A 50/50 mix of calculations and experiments can be carried out only within master thesis. A research line of this project also involves graphene-based structures and can be chosen for the thesis work.

B.Sc./FP-Project
Supervisor: Lorenzo Tesi

Goal: Determine the best parameters and procedures to obtain a homogenous thin layer of magnetic molecules diluted in a polymeric matrix.

Methods:

• Sample preparation by spin-coating with different conditions;
• Characterization by Optical Microscope, Atomic Force Microscopy, Profilometry;
• Data analysis with Python, Origin or Matlab;
• Applications with further techniques can occur depending on the specific project.

Background: Spin-coating is one of the best techniques existing for the fabrication of thin layers of polymeric species and is widely applied in academic as well as industry. Several parameters can be changed providing very different results (static or dynamic method, speed rate, acceleration, drop volume, concentration of the solution, etc.). Serious difficulties can occur when the substrate is small or has not-squared shapes, limiting spin-coating applications in many research areas.   

Tasks: A systematic study must be carried out in order to define the influence of the various parameters on the thin layer fabrication. All the possibilities should be investigated to identify the best protocol. Several magnetic molecules, as well as polymers and substrates will be used. Depending on the specific project further applications can represent an additional minor part of the work.