Detection of Heat Pulses by the Two-Dimensional Electron Gas in a Silicon Device

A silicon metal-oxide semiconductor field-effect transistor has been used to detect heat pulses generated by electrical heating of a thin metal film. In the presence of a quantizing magnetic field deep oscillations in the detected intensity are observed, the signal being a maximum when the Fermi level coincides with a Landau level. The appearance of an intermediate signal at higher heater temperatures is attributed to cyclotron phonon absorption. We show that this system can be used as a tunable phonon spectrometer.