Shot-noise signatures of 0.7 structure and spin in a quantum point contact.
We report simultaneous measurement of shot noise and dc transport in a quantum point contact as a function of source-drain bias, gate voltage, and in-plane magnetic field. Shot noise at zero field exhibits an asymmetry related to the 0.7 structure in conductance. The asymmetry in noise evolves smoothly into the symmetric signature of spin-resolved electron transmission at high field. Comparison to a phenomenological model with density-dependent level splitting yields good quantitative agreement.
DiCarlo
L
L
Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA.
Zhang
Y
Y
McClure
D T
DT
Reilly
D J
DJ
Marcus
C M
CM
Pfeiffer
L N
LN
West
K W
KW