Resistance Spikes at Transitions Between Quantum Hall Ferromagnets
E. P. De Poortere,*
E. Tutuc,
S. J. Papadakis,
M. Shayegan
We report a manifestation of first-order magnetic transitions in
two-dimensional electron systems. This phenomenon occurs in aluminum
arsenide quantum wells with sufficiently low carrier densities and
appears as a set of hysteretic spikes in the resistance of a sample
placed in crossed parallel and perpendicular magnetic fields, each
spike occurring at the transition between states with different partial
magnetizations. Our experiments thus indicate that the presence of
magnetic domains at the transition starkly increases dissipation, an
effect also suspected in other ferromagnetic materials. Analysis of the
positions of the transition spikes allows us to deduce the change in
exchange-correlation energy across the magnetic transition, which in
turn will help improve our understanding of metallic ferromagnetism.
Department of Electrical Engineering, Princeton University,
Princeton, NJ 08544, USA.
*
To whom correspondence should be addressed. E-mail:
poortere{at}ee.princeton.edu
