Disappearance of metal-like behavior in GaAs two-dimensional holes below 30 mK.
The zero-field temperature dependence of the resistivity of two-dimensional holes is observed to exhibit two qualitatively different characteristics for a fixed carrier density for which only the metallic behavior of the so-called metal-insulator transition is anticipated. As T is lowered from 150 to 0.5 mK, the sign of the derivative of the resistivity with respect to T changes from being positive to negative when the temperature is lowered below approximately 30 mK and the resistivity continuously rises with cooling down to 0.5 mK, suggesting a crossover from being metal-like to insulatorlike.
Huang
Jian
J
PRISM, Princeton University, Princeton, New Jersey 08544, USA.
Xia
J S
JS
Tsui
D C
DC
Pfeiffer
L N
LN
West
K W
KW