Group of Nanophysics

The nanophysics research at Jyväskylä has several main directions. Common to all of them are the fabrication and measurement facilities, which include a modern electron-beam lithography facility, several evaporators and many dilution refrigerators operating down to 40 mK, among others. Active development and optimization of fabrication and measurement processes continues in scanning-probe-based lithography, new resists technologies, and design and development of refrigerators.

One of the main research directions is thermal effects and transport in nanostructures. This subfield has both a basic and an applied component. The basic research concentrates in understanding how nano- and micro-scale electronic systems dissipate their heat into the solid substrates and how this heat is transported away from low-dimensional support structures. In terms of excitations, we can speak about the electron-phonon coupling and phonon thermal conductance. The applied part of the research tries to put this understanding into use in detector development. Thermal transport considerations are a limiting factor in many types of ultrasensitive radiation detectors that are actively studied in Jyväskylä. Novel FIR and mm-wave bolometer and X-ray calorimeter development is in progress and is supported by the ESA, this research aims to develop the detector technologies for the ESA XEUS mission.

In addition, electronic properties of superconducting nanostructures are also a major part of our activities. Jyväskylä is a member in an EU consortium, whose goal is to develop quantum gates (bits) based on the superconducting Josephson junction technology. We have succeeded in fabricating single electron transistors out of Niobium using traditional lift-off techniques, and further work on the feasibility of Nb as the quantum bit material is in progress.

Furthermore, the areas where Jyväskylä has gained a leading role world wide, namely CBT thermometry and NIS- microrefrigeration, continue to be studied and applied. The CBT development is conducted in close collaboration with Nanoway Oy, who have commercialized the CBT technology into a working primary nanoscale thermometer. Microrefrigeration research has concentrated recently on the issue of semiconductor cooling, with quite promising results. The semiconductor research is conducted in collaboration with the National Research Center VTT.

link: www.phys.jyu.fi/research/nanotech/index.html