New class of magnetoresistance oscillations: interaction of a two-dimensional electron gas with leaky interface phonons.
We report on a new class of magnetoresistance oscillations observed in a high-mobility two-dimensional electron gas (2DEG) in GaAs-Al(x)Ga(1--x)As heterostructures. Appearing in a weak magnetic field ( B < 0.3 T) and only in a narrow temperature range ( 2 K < T < 9 K), these oscillations are periodic in 1/B with a frequency proportional to the electron Fermi wave vector, k(F). We interpret the effect as a magnetophonon resonance of the 2DEG with leaky interface-acoustic phonon modes carrying a wave vector q = 2k(F). Calculations show a few branches of such modes existing on the GaAs-Al(x)Ga(1--)xAs interface, and their velocities are in quantitative agreement with the observation.
Zudov
M A
MA
Department of Physics, University of Utah, Salt Lake City, Utah 84112, USA.
Ponomarev
I V
IV
Efros
A L
AL
Du
R R
RR
Simmons
J A
JA
Reno
J L
JL