260 research outputs found
Formation of defects in multirow Wigner crystals
We study the structural properties of a quasi-one-dimensional classical
Wigner crystal, confined in the transverse direction by a parabolic potential.
With increasing density, the one-dimensional crystal first splits into a zigzag
crystal before progressively more rows appear. While up to four rows the ground
state possesses a regular structure, five-row crystals exhibit defects in a
certain density regime. We identify two phases with different types of defects.
Furthermore, using a simplified model, we show that beyond nine rows no stable
regular structures exist.Comment: 11 pages, 8 figure
Optical exciton Aharonov-Bohm effect, persistent current, and magnetization in semiconductor nanorings of type I and II
The optical exciton Aharonov-Bohm effect, i. e. an oscillatory component in
the energy of optically active (bright) states, is investigated in nanorings.
It is shown that a small effective electron mass, strong confinement of the
electron, and high barrier for the hole, achieved e. g. by an InAs nanoring
embedded in an AlGaSb quantum well, are favorable for observing the optical
exciton Aharonov-Bohm effect. The second derivative of the exciton energy with
respect to the magnetic field is utilized to extract Aharonov-Bohm oscillations
even for the lowest bright state unambiguously. A connection between the
theories for infinitesimal narrow and finite width rings is established.
Furthermore, the magnetization is compared to the persistent current, which
oscillates periodically with the magnetic field and confirms thus the
non-trivial (connected) topology of the wave function in the nanoring.Comment: 12 pages, 11 figure
Some Exact Solutions For The Classical Hall Effect In Inhomogeneous Magnetic Field
The classical Hall effect in inhomogeneous systems is considered for the case
of one-dimensional inhomogeneity. For a certain geometry of the problem and for
the magnetic field linearly depending on the coordinate the density of current
distribution corresponds to the skin-effect.Comment: 5 pages, LaTe
Observable Bulk Signatures of Non-Abelian Quantum Hall States
We show that non-abelian quantum Hall states can be identified by
experimental measurements of the temperature-dependence of either the
electrochemical potential or the orbital magnetization. The predicted signals
of non-abelian statistics are within experimental resolution, and can be
clearly distinguished from other contributions under realistic circumstances.
The proposed measurement technique also has the potential to resolve
spin-ordering transitions in low density electronic systems in the Wigner
crystal and strongly-interacting Luttinger liquid regimes.Comment: Minor change
Acoustic surface plasmons in the noble metals Cu, Ag, and Au
We have performed self-consistent calculations of the dynamical response of
the (111) surface of the noble metals Cu, Ag, and Au. Our results indicate that
the partially occupied surface-state band in these materials yields the
existence of acoustic surface plasmons with linear dispersion at small wave
vectors. Here we demonstrate that the sound velocity of these low-energy
collective excitations, which had already been predicted to exist in the case
of Be(0001), is dictated not only by the Fermi velocity of the two-dimensional
surface-state band but also by the nature of the decay and penetration of the
surface-state orbitals into the solid. Our linewidth calculations indicate that
acoustic surface plasmons should be well defined in the energy range from zero
to meV.Comment: 8 pages, two columns, 7 figures, to appear in Phys. Rev.
- …