8 research outputs found
Spin-blockade spectroscopy of a two-level artificial molecule
Coulomb and spin blockade spectroscopy investigations have been performed on
an electrostatically defined ``artificial molecule'' connected to spin
polarized leads. The molecule is first effectively reduced to a two-level
system by placing both constituent atoms at a specific location of the level
spectrum. The spin sensitivity of the conductance enables us to identify the
electronic spin-states of the two-level molecule. We find in addition that the
magnetic field induces variations in the tunnel coupling between the two atoms.
The lateral nature of the device is evoked to explain this behavior.Comment: 4 pages, 4 figures; revised version with a minor change in Fig.2 and
additional inset in Fig.3.;accepted by PR
Aharonov-Bohm Oscillations in Photoluminescence from Charged Exciton in Quantum Tubes
The oscillation of photoluminescence peak energies is observed in InAs
quantum tubes depending on the magnetic flux through the tube. The oscillation
is shown to be due to the Aharonov-Bohm effect of a charged exciton in a
quantum tube. No quadratic shift in photoluminescence peak energies is
observed, which is a characteristic feature of a thin quantum tube with a
single channel surrounding the magnetic flux through the tube.Comment: 14 pages, 4 figure
Configuration interaction method for Fock-Darwin states
We present a configuration interaction method optimized for Fock-Darwin
states of two-dimensional quantum dots with an axially symmetric, parabolic
confinement potential subject to a perpendicular magnetic field. The
optimization explicitly accounts for geometrical and dynamical symmetries of
the Fock-Darwin single-particle states and for many-particle symmetries
associated with the center-of-mass motion and with the total spin. This results
in a basis set of reduced size and improved accuracy. The numerical results
compare well with the quantum Monte Carlo and stochastic variational methods.
The method is illustrated by the evolution of a strongly correlated
few-electron droplet in a magnetic field in the regime of the fractional
quantum Hall effect.Comment: 17 pages, 3 figures, ReVTeX4, submitted to Solid State Communication