Ongoing progress in cooling nanoelectronics circuits is currently opening up the range of low millikelvin and even microkelvin temperatures for experiments, thus giving access to unprecedented low temperatures. This can be the key to create novel quantum states of matter such as nuclear spin phases, full nuclear spin polarization, quantum Hall ferromagnets or fragile fractional quantum Hall states. In addition, quantum coherence would be significantly boosted, which benefits solid state quantum bits and quantum interference experiments.

This minicolloquium will encompass the recent experimental and theoretical developments in ultralow-temperature nanoscale devices both from the quantum transport and thermodynamics perspective.

The scientific content will range from helium immersion cell cooling as well as on-and-off chip cooling with adiabatic demagnetization of Coulomb blockade thermometers to the experimental detection of nuclear spin ordering and related theoretical models. We will target to discuss predictions on the applicability of these cooling techniques to more general nanostructures and samples such as semiconductors, topological insulators and other quantum materials.