Electron correlation in the second Landau level: a competition between many nearly degenerate quantum phases.
At a very low-temperature of 9 mK, electrons in the second Landau level of an extremely high-mobility two-dimensional electron system exhibit a very complex electronic behavior. With a varying filling factor, quantum liquids of different origins compete with several insulating phases leading to an irregular pattern in the transport parameters. We observe a fully developed nu=2+2/5 state separated from the even-denominator nu=2+1/2 state by an insulating phase and a nu=2+2/7 and nu=2+1/5 state surrounded by such phases. A developing plateau at nu=2+3/8 points to the existence of other even-denominator states.
Xia
J S
JS
University of Florida, Gainesville, Florida 32611, USA.
Pan
W
W
Vicente
C L
CL
Adams
E D
ED
Sullivan
N S
NS
Stormer
H L
HL
Tsui
D C
DC
Pfeiffer
L N
LN
Baldwin
K W
KW
West
K W
KW