Contrasting behavior of the 5/2 and 7/3 fractional quantum Hall effect in a tilted field.
Using a tilted-field geometry, the effect of an in-plane magnetic field on the even denominator nu=5/2 fractional quantum Hall state is studied. The energy gap of the nu=5/2 state is found to collapse linearly with the in-plane magnetic field above approximately 0.5 T. In contrast, a strong enhancement of the gap is observed for the nu=7/3 state. The radically distinct tilted-field behavior between the two states is discussed in terms of Zeeman and magneto-orbital coupling within the context of the proposed Moore-Read Pfaffian wave function for the 5/2 fractional quantum Hall effect.
Dean
C R
CR
Department of Physics, McGill University, Montreal, H3A 2T8, Canada.
Piot
B A
BA
Hayden
P
P
Das Sarma
S
S
Gervais
G
G
Pfeiffer
L N
LN
West
K W
KW