Cooling Electrons in Nanoelectronic Devices by On-Chip Demagnetisation

This thesis demonstrates that an ultralow temperature refrigeration technique called "demagnetisation refrigeration" can be miniaturised and incorporated onto millimeter-sized chips to cool nanoelectronic circuits, devices and materials. Until recently, the lowest temperature ever reached in such systems was around 4 millikelvin. Here, a temperature of 1.2mK is reported in a nanoelectronic device. The thesis introduces the idea that on-chip demagnetization refrigeration can be used to cool ...