3,790 research outputs found
The noise spectra of a biased quantum dot
The noise spectra associated with correlations of the current through a
single level quantum dot, and with the charge fluctuations on the dot, are
calculated for a finite bias voltage. The results turn out to be sensitive to
the asymmetry of the dot's coupling to the two leads. At zero temperature, both
spectra exhibit two or four steps (as a function of the frequency), depending
on whether the resonant level lies outside or within the range between the
chemical potentials on the two leads. In addition, the low frequency shot-noise
exhibits dips in the charge noise and dips, peaks, and discontinuities in the
derivative of the current noise. In spite of some smearing, several of these
features persist at finite temperatures, where a dip can also turn into a peak
Investigation of the feasibility of sterile assembly of silver-zinc batteries
Electrical performance, bioassays, and packaging concepts evaluated in sterile assembly of silver zinc batterie
Noise spectra of an interacting quantum dot
We study the noise spectra of a many-level quantum dot coupled to two
electron reservoirs, when interactions are taken into account only on the dot
within the Hartree-Fock approximation. The dependence of the noise spectra on
the interaction strength, the coupling to the leads, and the chemical potential
is derived. For zero bias and zero temperature, we find that as a function of
the (external) frequency, the noise exhibits steps and dips at frequencies
reflecting the internal structure of the energy levels on the dot.
Modifications due to a finite bias and finite temperatures are investigated for
a non-interacting two-level dot. Possible relations to experiments are pointed
out.Comment: Added reference
Finite size corrections to the radiation reaction force in classical electrodynamics
We introduce an effective field theory approach that describes the motion of
finite size objects under the influence of electromagnetic fields. We prove
that leading order effects due to the finite radius of a spherically
symmetric charge is order rather than order in any physical model, as
widely claimed in the literature. This scaling arises as a consequence of
Poincar\'e and gauge symmetries, which can be shown to exclude linear
corrections. We use the formalism to calculate the leading order finite size
correction to the Abraham-Lorentz-Dirac force.Comment: 4 pages, 2 figure
Next to leading order spin-orbit effects in the motion of inspiralling compact binaries
Using effective field theory (EFT) techniques we calculate the
next-to-leading order (NLO) spin-orbit contributions to the gravitational
potential of inspiralling compact binaries. We use the covariant spin
supplementarity condition (SSC), and explicitly prove the equivalence with
previous results by Faye et al. in arXiv:gr-qc/0605139. We also show that the
direct application of the Newton-Wigner SSC at the level of the action leads to
the correct dynamics using a canonical (Dirac) algebra. This paper then
completes the calculation of the necessary spin dynamics within the EFT
formalism that will be used in a separate paper to compute the spin
contributions to the energy flux and phase evolution to NLO.Comment: 25 pages, 4 figures, revtex4. v2: minor changes, refs. added. To
appear in Class. Quant. Gra
A nonlinear scalar model of extreme mass ratio inspirals in effective field theory I. Self force through third order
The motion of a small compact object in a background spacetime is
investigated in the context of a model nonlinear scalar field theory. This
model is constructed to have a perturbative structure analogous to the General
Relativistic description of extreme mass ratio inspirals (EMRIs). We apply the
effective field theory approach to this model and calculate the finite part of
the self force on the small compact object through third order in the ratio of
the size of the compact object to the curvature scale of the background (e.g.,
black hole) spacetime. We use well-known renormalization methods and
demonstrate the consistency of the formalism in rendering the self force finite
at higher orders within a point particle prescription for the small compact
object. This nonlinear scalar model should be useful for studying various
aspects of higher-order self force effects in EMRIs but within a comparatively
simpler context than the full gravitational case. These aspects include
developing practical schemes for higher order self force numerical
computations, quantifying the effects of transient resonances on EMRI waveforms
and accurately modeling the small compact object's motion for precise
determinations of the parameters of detected EMRI sources.Comment: 30 pages, 8 figure
Spectral Difference Equations Satisfied by KP Soliton Wavefunctions
The Baker-Akhiezer (wave) functions corresponding to soliton solutions of the
KP hierarchy are shown to satisfy eigenvalue equations for a commutative ring
of translational operators in the spectral parameter. In the rational limit,
these translational operators converge to the differential operators in the
spectral parameter previously discussed as part of the theory of
"bispectrality". Consequently, these translational operators can be seen as
demonstrating a form of bispectrality for the non-rational solitons as well.Comment: to appear in "Inverse Problems
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