24,672 research outputs found
Tuning the tunnel coupling of quantum dot molecules with longitudinal magnetic fields
We show that the energy splitting between the bonding and antibonding
molecular states of holes in vertically stacked quantum dots can be tuned using
longitudinal magnetic fields. With increasing field, the energy splitting first
decreases down to zero and then to negative values, which implies a
bonding-to-antibonding ground state transition. This effect is a consequence of
the enhancement of the valence band spin-orbit interaction induced by the
magnetic field, and it provides a flexible mechanism to switch the molecular
ground state from bonding to antibonding.Comment: 4 pages, 3 figs; accepted by Applied Physics Letters. After it is
published it will be found at http://apl.aip.org
The Role of Alternance Symmetry in Magnetoconductance
We show that the direction of coherent electron transport across a cyclic
system of quantum dots or a cyclic molecule can be modulated by an external
magnetic field if the cycle has an odd number of hopping sites, but the
transport becomes completely symmetric if the number is even. These contrasting
behaviors, which remain in the case of interacting electrons, are a consequence
of the absence or presence of alternance symmetry in the system. These findings
are relevant for the design of nanocircuits based on coupled quantum dots or
molecular junctions.Comment: to be published in PR
Smart random walkers: the cost of knowing the path
In this work we study the problem of targeting signals in networks using
entropy information measurements to quantify the cost of targeting. We
introduce a penalization rule that imposes a restriction to the long paths and
therefore focus the signal to the target. By this scheme we go continuously
from fully random walkers to walkers biased to the target. We found that the
optimal degree of penalization is mainly determined by the topology of the
network. By analyzing several examples, we have found that a small amount of
penalization reduces considerably the typical walk length, and from this we
conclude that a network can be efficiently navigated with restricted
information.Comment: 9 pages, 11 figure
ALICE Diffractive Detector Control System for RUN-II in the ALICE Experiment
This paper describes general characteristics of the deployment and
commissioned of the Detector Control System (DCS) AD0 for the second phase of
the Large Hadron Collider (LHC). The AD0 detector is installed in the ALICE
experiment to provide a better selection of diffractive events.Comment: 4 pages, 5 figures, To be published in Journal of Physics Conference
Series (IOP). Joint Proceedings of the XV Mexican Workshop on Particles and
Fields & the XXX Annual Meeting of the Division of Particles and Fields of
the Mexican Physical Societ
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