Spatial imaging of two-dimensional electronic states in semiconductor quantum wells.
We measure the spatial distribution of the local density of states (LDOS) at cleaved surfaces of InAs/GaSb isolated quantum wells and double quantum wells (DQWs) by low-temperature scanning tunneling spectroscopy. Distinct standing wave patterns of LDOS corresponding to subbands are observed. These LDOS patterns and subband energies agree remarkably well with simple calculations with tip-induced band bending. Furthermore, for the DQWs, coupling of electronic states between the quantum wells is also clearly observed.
Suzuki
K
K
NTT Basic Research Laboratories, NTT Corporation, Atsugi-shi, Kanagawa 243-0198, Japan. kyoichi@will.brl.ntt.co.jp
Kanisawa
K
K
Janer
C
C
Perraud
S
S
Takashina
K
K
Fujisawa
T
T
Hirayama
Y
Y