Semiconductor Physics, Quantum Electronics & Optoelectronics. 2000. V. 3, N 4. P. 432-437.

PACS: 63.22, 72.20, 73.20.D

Generation of coherent confined acoustic phonons
by drifting electrons in quantum wire

Institute of Semiconductor Physics, NAS Ukraine, 45 Prospect Nauki, Kyiv, 03028, Ukraine
E-mail: kochelap@nika1.pp.kiev.ua

Abstract. We developed a quantum theory of generation of coherent confined acoustic phonons by one-dimensional electrons drifting in a quantum wire. A general formula for the factor of amplification of the phonon flux, a, is derived. When the electron drift velocity, V_d, is greater than the sound phase velocity, S, then at low temperatures the above generation occurs only in a narrow range of phonon wave vectors, q ~ 2k_F[1 ± (V_d _ S)/V_F], where k_F (V_F) is the wave vector (Fermi velocity) of one-dimensional electrons. Estimation gives for a the value of about 10³cm^-1 in the subTHz frequency range.

Keywords: acoustic wave localization, acoustic wave amplification, electron drift, quantum wire.

Paper received 18.02.00; revised manuscript received 13.11.00; accepted for publication 12.12.00.