1,332,367 research outputs found
Electric-Field Guided Precision Manipulation of Catalytic Nanomotors for Cargo Delivery and Powering Nanoelectromechanical Devices
We report a controllable and precision approach in manipulating catalytic
nanomotors by strategically applied electric (E-) fields in three dimensions
(3-D). With the high controllability, the catalytic nanomotors have
demonstrated new versa-tility in capturing, delivering, and releasing of cargos
to designated locations as well as in-situ integration with nanome-chanical
devices (NEMS) to chemically power the actuation. With combined AC and DC
E-fields, catalytic nanomotors can be accurately aligned by the AC E-fields and
instantly change their speeds by the DC E-fields. Within the 3-D orthog-onal
microelectrode sets, the in-plane transport of catalytic nanomotors can be
swiftly turned on and off, and these cata-lytic nanomotors can also move in the
vertical direction. The interplaying nanoforces that govern the propulsion and
alignment are investigated. The modeling of catalytic nanomotors proposed in
previous works has been confirmed quan-titatively here. Finally, the prowess of
the precision manipulation of catalytic nanomotors by E-fields is demonstrated
in two applications: the capture, transport, and release of cargos to
pre-patterned microdocks, and the assembly of catalytic nanomotors on NEMS to
power the continuous rotation. The innovative concepts and approaches reported
in this work could further advance ideal applications of catalytic nanomotors,
e.g. for assembling and powering nanomachines, nano-robots, and complex NEMS
devices
Effects of a static electric field on two-color photoassociation between different atoms
We study non-perturbative effects of a static electric field on two-color
photoassociation of different atoms. A static electric field induces anisotropy
in scattering between two different atoms and hybridizes field-free rotational
states of heteronuclear dimers or polar molecules. In a previous paper [D.
Chakraborty , J. Phys. B 44, 095201 (2011)], the effects
of a static electric field on one-color photoassociation between different
atoms has been described through field-modified ground-state scattering states,
neglecting electric field effects on heteronuclear diatomic bound states. To
study the effects of a static electric field on heteronuclear bound states, and
the resulting influence on Raman-type two-color photoassociation between
different atoms in the presence of a static electric field, we develop a
non-perturbative numerical method to calculate static electric field-dressed
heteronuclear bound states. We show that the static electric field induced
scattering anisotropy as well as hybridization of rotational states strongly
influence two-color photoassociation spectra, leading to significant
enhancement in PA rate and large shift. In particular, for static electric
field strengths of a few hundred kV/cm, two-color PA rate involving high-lying
bound states in electronic ground-state increases by several orders of
magnitude even in the weak photoassociative coupling regime
Role of the radiation-reaction electric field in the optical response of two-dimensional crystals
A classical theory of a radiating two-dimensional crystal is proposed and an
expression for the radiative-reaction electric field is derived. This field
plays an essential role in connecting the microscopic electromagnetic fields
acting on each dipole of the crystal to the macroscopic one, via the boundary
conditions for the system. The expression of the radiative-reaction electric
field coincides with the macroscopic electric field radiating from the crystal
and, summed to the incident electric field, generates the total macroscopic
electric field.Comment: Two-dimensional crystal, metasurface, local field,
radiative-reaction, Fresnel, boundary conditio
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