Antenna coupled direct detector for millimetre and submillimetre astronomy based on 2D electron gas in semiconducting heterostructure

The energy resolution of a detector is related to the figure of merit NEP × √τ which is proportional to the heat capacity of the detector. Hot electron (cold electron) devices have much lower heat capacity than bolometers with silicon nitride based thermal isolation. Traditional hot electron bolometers (HEB) require sub-micron fabrication for use at submm wavelengths and it is difficult to simultaneously couple radiation and read out these devices. The 2D electron gas (2DEG) in a semiconductor heterojunction effectively acts as a metal film with a thickness of a few angstroms and a tunable density and electron mobility. We describe a HEB that uses a 2DEG as an absorber and present simulations of optical coupling schemes for this type of detector including an antenna coupled to a coplanar waveguide with distributed 2DEG absorbers.