[Magnetic-field-induced nonthermal occupation of higher subbands in a three-barrier tunneling structure].
When injected electrons in a quantum well first experience an intersubband relaxation process before their escaping by tunneling through a double-barrier structure behind, the magnetic suppression of intersubband LO or LA phonon scattering can give rise to a noticeable nonthermal occupation in higher-lying subbands. That is clearly verified by the relative intensity ratio of the interband photoluminescence spectra for E2-HH1 and E1-HH1 transitions. The observed phenomenon may provide an effective method for controlling intersubband scattering rate, a central issue in so-called quantum cascade lasers, and facilitating the population inversion between subbands in quantum wells.
An
Long
L
National Laboratory for Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China.
Tang
Yan
Y
Zhang
Ji-dong
JD
Ji
Yang
Y
Tan
Ping-heng
PH
Yang
Fu-hua
FH
Zheng
Hou-zhi
HZ