Open positions / projects

Abstract:
Superconducting circuits are the basis for quantum technology. Usually, superconductors are fabricated in thin-film form and patterned by lithography. Here you will explore a different approach: Solidifying a gaseous precursor of WCO₆ under strong ion irradiation is a method to directly grow superconductors onto any surfaces.

Research question:
How do the superconducting properties like the transition temperature, T_c, depend on the ion beam conditions? Can you optimize T_c?

Learning goals:
Basics of superconductivity; Nanodeposition with ion beams; electric transport measurements using lock-in amplifiers; experiments at low temperatures and high magnetic fields (T<2K, B>=14T); compositional analysis methods (EDX)

Abstract:
Topological semi-metals are a new class of materials in which electrons behave like massless particles. Their unique properties lead to highly unusual materials behavior, which we hope to harness in future technology. One of their properties is an unusually strong, paramagnetic response in strong magnetic fields. Using on-chip magnetometry, you can search for this quantum property in LaRhIn₅.

Research question:
Are there magnetic signatures of massless electrons in crystals of LaRhIn₅ and CeRhIn₅?

Learning goals:
Basics of topological matter; electric transport measurements using lock-in amplifiers; experiments at low temperatures and high magnetic fields (T<2K, B>=14T); magnetometry

Abstract:
Conductive oxides are spectacular materials. They host record-high temperature superconductivity, magnetism and often phase-change properties. An important issue towards their applications is the difficulty to form electric contacts to metals. You would explore a new fabrication route based on nanoparticles.

Research question:
Can metallic nanoparticles enhance surface diffusion to facilitate electric current flow?

Learning goals:
Metal diffusion through oxides; high-temperature annealing oven; electric transport measurements using lock-in amplifiers; experiments at low temperatures and high magnetic fields (T<2K, B>=14T)

Abstract:
Superconducting circuits are the basis for quantum technology. By solidifying a gaseous precursor of WCO6 under strong ion irradiation, a superconducting film can be grown. The carbon concentration critically determines the superconducting transition.

Research question:
Can you modify the superconducting transition temperature, Tc, by applying a new prototype “plasma pen”? The idea is that local ozone could react with, and remove, excess carbon in the film.

Learning goals:
Basics of superconductivity; Nanodeposition with ion beams; electric transport measurements; experiments at low temperatures and high magnetic fields (T<2K, B>=14T); compositional analysis methods (EDX)

Abstract:
In a FIB, a gaseous precursor can be locally solidified by ion-assisted chemical vapor deposition. The deposited films are Pt-rich, and host an intricate microstructure consisting of Pt nanocrystals embedded in a carbon matrix. Little is known about the dynamical mechanics of these materials

Research question:
Can you make a free-standing Pt cantilever, and measure its resonance frequency? From there, can you compute the elastic modulus and obtain a Q-factor?

Learning goals:
Nanodeposition with ion beams; interferometric optical measurements; resonant detection scheme; experiments at low temperatures; compositional analysis methods (EDX)

Abstract:
Recently, we noticed that bismuth patches, when connected to gold thin films, form nano-wires following the gold morphology. This is a rather strange growth process that we would like to study in more detail.

Research question:
If we deposit Bi patches onto Au films, can you induce this nano-wire growth and, if so, determine its growth parameters?

Learning goals:
Nanodeposition with ion beams; manipulation of Bi microstructures; compositional analysis methods (EDX)