Experimental mesoscopic physics: properties of micrometer and nanometer scale devices at low temperatures. Heat transport in proximity-coupled normal metals and superconductors; spin-polarized transport in ferromagnet/normal-metal and ferromagnet/superconductor heterostructures; electrical and thermal transport in carbon nanotube and graphene devices; millikelvin range scanning probe and scanning tunneling microscopy; transport and magnetization dynamics in nanomagnets; magnetic, surface and electrical properties of complex oxides. High frequency instrumentation and measurement; quantum state manipulation.