Direct measurements of fractional quantum Hall effect gaps.
We measure the chemical potential jump across the fractional gap in the low-temperature limit in the two-dimensional electron system of GaAs/AlGaAs single heterojunctions. In the fully spin-polarized regime, the gap for filling factor nu=1/3 increases linearly with the magnetic field and is coincident with that for nu=2/3, reflecting the electron-hole symmetry in the spin-split Landau level. In low magnetic fields, at the ground-state spin transition for nu=2/3, a correlated behavior of the nu=1/3 and nu=2/3 gaps is observed.
Khrapai
V S
VS
Institute of Solid State Physics, Chernogolovka, Moscow District, Russia.
Shashkin
A A
AA
Trokina
M G
MG
Dolgopolov
V T
VT
Pellegrini
V
V
Beltram
F
F
Biasiol
G
G
Sorba
L
L
D003080:Cold Temperature; D004583:Electrons; D060526:Magnetic Fields; D011789:Quantum Theory