Abstract
Landau damping of each phonon mode causes its spectral density to acquire a low-frequency tail proportional to 2. Consequently the T3 low-temperature heat capacity arising from acoustic modes, with a frequency spectrum proportional to 2, is supplemented by the spectral-density tails from all modes in the Brillouin zone. This extra term is proportional to T3ln(T) and is a few percent of the Debye term at 1 K. In metals with large electron-phonon interaction e.g., superconductors the extra term will be larger, and will be present only in the normal state. A lower T3 coefficient should occur in the superconducting state, a phenomenon reported experimentally for indium 20 years ago, since the spectral-density tail falls to zero for frequencies below the energy gap.
Original language | English |
---|---|
Pages (from-to) | 1569-1573 |
Number of pages | 5 |
Journal | Physical Review B |
Volume | 26 |
Issue number | 4 |
DOIs | |
State | Published - 1982 |
Externally published | Yes |