7,494 research outputs found
Surface Acoustic Wave Single-Electron Interferometry
We propose an experiment to observe interference of a single electron as it
is transported along two parallel quasi-one-dimensional channels trapped in a
single minimum of a travelling periodic electric field. The experimental device
is a modification of the surface acoustic wave (SAW) based quantum processor.
Interference is achieved by creating a superposition of spatial wavefunctions
between the two channels and inducing a relative phase shift via either a
transverse electric field or a magnetic field. The interference can be used to
estimate the decoherence time of an electron in this type of solid-state
device
Nonlinear acousto-magneto-plasmonics
We review the recent progress in experimental and theoretical research of
interactions between the acoustic, magnetic and plasmonic transients in hybrid
metal-ferromagnet multilayer structures excited by ultrashort laser pulses. The
main focus is on understanding the nonlinear aspects of the acoustic dynamics
in materials as well as the peculiarities in the nonlinear optical and
magneto-optical response. For example, the nonlinear optical detection is
illustrated in details by probing the static magneto-optical second harmonic
generation in gold-cobalt-silver trilayer structures in Kretschmann geometry.
Furthermore, we show experimentally how the nonlinear reshaping of giant
ultrashort acoustic pulses propagating in gold can be quantified by
time-resolved plasmonic interferometry and how these ultrashort optical pulses
dynamically modulate the optical nonlinearities. The effective medium
approximation for the optical properties of hybrid multilayers facilitates the
understanding of novel optical detection techniques. In the discussion we
highlight recent works on the nonlinear magneto-elastic interactions, and
strain-induced effects in semiconductor quantum dots.Comment: 30 pages, 12 figures, to be published as a Topical Review in the
Journal of Optic
Femtosecond nonlinear ultrasonics in gold probed with ultrashort surface plasmons
Fundamental interactions induced by lattice vibrations on ultrafast time
scales become increasingly important for modern nanoscience and technology.
Experimental access to the physical properties of acoustic phonons in the THz
frequency range and over the entire Brillouin zone is crucial for understanding
electric and thermal transport in solids and their compounds. Here, we report
on the generation and nonlinear propagation of giant (1 percent) acoustic
strain pulses in hybrid gold/cobalt bilayer structures probed with ultrafast
surface plasmon interferometry. This new technique allows for unambiguous
characterization of arbitrary ultrafast acoustic transients. The giant acoustic
pulses experience substantial nonlinear reshaping already after a propagation
distance of 100 nm in a crystalline gold layer. Excellent agreement with the
Korteveg-de Vries model points to future quantitative nonlinear femtosecond
THz-ultrasonics at the nano-scale in metals at room temperature
A Common-Path Interferometer for Time-Resolved and Shot-Noise-Limited Detection of Single Nanoparticles
We give a detailed description of a novel method for time-resolved
experiments on single non-luminescent nanoparticles. The method is based on the
combination of pump-probe spectroscopy and a common-path interferometer. In our
interferometer, probe and reference arms are separated in time and polarization
by a birefringent crystal. The interferometer, fully described by an analytical
model, allows us to separately detect the real and imaginary contributions to
the signal. We demonstrate the possibilities of the setup by time-resolved
detection of single gold nanoparticles as small as 10 nm in diameter, and of
acoustic oscillations of particles larger than 40 nm in diameter
Size Constraints on Majorana Beamsplitter Interferometer: Majorana Coupling and Surface-Bulk Scattering
Topological insulator surfaces in proximity to superconductors have been
proposed as a way to produce Majorana fermions in condensed matter physics. One
of the simplest proposed experiments with such a system is Majorana
interferometry. Here, we consider two possibly conflicting constraints on the
size of such an interferometer. Coupling of a Majorana mode from the edge (the
arms) of the interferometer to vortices in the centre of the device sets a
lower bound on the size of the device. On the other hand, scattering to the
usually imperfectly insulating bulk sets an upper bound. From estimates of
experimental parameters, we find that typical samples may have no size window
in which the Majorana interferometer can operate, implying that a new
generation of more highly insulating samples must be explored.Comment: 14 pages, 6 figure
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