Quantum-Coherent Transport in Quantum Hall Devices V. J. Goldman, Stony Brook University, DMR-0303705

1
Quantum-Coherent Transportin Quantum Hall
DevicesV. J. Goldman, Stony Brook University,
DMR-0303705
We have fabricated Aharonov-Bohm
electron interferometers, operating in very high
magnetic fields and ultra-low temperatures. An
atomic force microscope (AFM) image of a typical
device is shown. The electrons are constrained
to move in a 2D plane, 300 nm below the
semiconductor surface. Four gold gates are used
to control tunneling and the symmetry of the
device. Experiments show characteristic quantum
interference patterns for both electrons and
fractionally-charged Laughlin quasiparticles. For
the first time ever, we observe Aharonov- Bohm
superperiod, a period more than the h/e
fundamental flux quantum. The results are
interpreted as a direct demonstration of a
fractional statistics of Laughlin
quasiparticles. Physical Review B 72, 075342
(2005)
2
Quantum-Coherent Transportin Quantum Hall
DevicesV. J. Goldman, Stony Brook University,
DMR-0303705
Education Two graduate (Wei Zhou, Jie Yu), one
undergraduate (Jia G. Li, female) and one postdoc
(Dr. Fernando E. Camino) worked on research
supported by this NSF Award. The lab web site
http//quantum.physics.sunysb.edu/ contains
pictures and description of equipment and
facilities, and recent research presentations. It
is also used in education as the web site of
classes taught by Prof. Goldman. It averages 2000
hits per month from all over the world.
Societal Impact The ability to transport
electrons and fractional quasiparticles
quantum-coherently is a very powerful technique.
It promises to lead to the development of new
kinds of electronic devices, including quantum
computers. First experimental demonstration of
fractional statistics is of a fundamental
importance for basic science.