Resistivity of dilute 2D electrons in an undoped GaAs heterostructure.
We report resistivity measurements from 0.03 to 10 K in a dilute high mobility 2D electron system. Using an undoped GaAs/AlGaAs heterojunction in a gated field-effect transistor geometry, a wide range of densities, 0.16 x 10(10) to 7.5 x 10(10) cm(-2), are explored. For high densities, the results are quantitatively shown to be due to scattering by acoustic phonons and impurities. In an intermediate range of densities, a peak in the resistivity is observed for temperatures below 1 K. This nonmonotonic resistivity can be understood by considering the known scattering mechanisms of phonons, bulk, and interface ionized impurities. Still lower densities appear insulating to the lowest temperature measured.
Lilly
M P
MP
Sandia National Laboratories, Albuquerque, New Mexico 87185, USA.
Reno
J L
JL
Simmons
J A
JA
Spielman
I B
IB
Eisenstein
J P
JP
Pfeiffer
L N
LN
West
K W
KW
Hwang
E H
EH
Das Sarma
S
S