Tin- and lead-tunnel junctions as quantitative detector for intense thermal phonon pulses
| Autor: | M. Nover, O. Weis |
|---|---|
| Rok vydání: | 1981 |
| Předmět: |
Thermal equilibrium
Superconductivity Materials science Condensed matter physics Phonon Constantan chemistry.chemical_element Condensed Matter::Mesoscopic Systems and Quantum Hall Effect Condensed Matter Physics Electronic Optical and Magnetic Materials Condensed Matter::Materials Science chemistry Condensed Matter::Superconductivity Attenuation coefficient Sapphire Tin Diode |
| Zdroj: | Zeitschrift f�r Physik B Condensed Matter. 41:195-203 |
| ISSN: | 1434-6036 0340-224X |
| Popis: | Pulse-heated constantan films emit thermal phonon pulses into an a-cut sapphire held at a temperature of some Kelvin. The frequencies of these thermal phonons depend on the radiation temperature and can easily be shifted into the THz range. After a path of 6 mm these phonons are detected by observing the momentary current/voltage characteristics of evaporated symmetric tin- or lead-tunnel junctions during irradiation time. These characteristics correspond to characteristics taken in thermal equilibrium at higher substrate temperature which means that a momentary temperature of the electronic system can be deduced. Using a set of model assumptions concerning phonon transmission across interfaces, phonon propagation in the anisotropic sapphire, absorption in the superconducting detector film and reemission of the absorbed power into the substrate, a comparison with theoretically expected diode temperatures within the ‘one-temperature model’ for the detector material can be made. Using a variety of quite different experimental conditions there is a remarkable and astonishing well agreement between experiment and theory by fitting only two parameters for each phonon polarization and metal:i) the phonon absorption coefficient in the normal state andii) a phonon cutoff-frequency for the detected phonons. From this fit an information about these important, so far unknown parameters is achieved. |
| Databáze: | OpenAIRE |
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