28,463 research outputs found
Rotational cavity optomechanics
We theoretically examine the optomechanical interaction between a rotating
nanoparticle and an orbital angular momentum-carrying optical cavity mode.
Specifically, we consider a dielectric nanosphere rotating uniformly in a
ring-shaped optical potential inside a Fabry-Perot resonator. The motion of the
particle is probed by a weak angular lattice, created by introducing two
additional degenerate Laguerre-Gaussian cavity modes carrying equal and
opposite orbital angular momenta. We demonstrate that the rotation frequency of
the nanoparticle is imprinted on the probe optical mode, via the Doppler shift,
and thus may be sensed experimentally using homodyne detection. We show
analytically that the effect of the optical probe on the particle rotation
vanishes in the regime of linear response, resulting in an accurate frequency
measurement. We also numerically characterize the degradation of the
measurement accuracy when the system is driven in the nonlinear regime. Our
results are relevant to rotational Doppler velocimetry and to studies of
rotational Brownian motion in a periodic lattice.Comment: 7 pages, 2 figures, to appear in JOSA
Stereochemical properties of the OH molecule in combined electric and magnetic fields: analytic results
The stereochemical properties of the ultracold ground state OH molecule in
the presence of electric and magnetic fields are currently of considerable
interest. For example, relevant quantities such as molecular alignment and
orientation, calculated numerically by using large basis sets, have lately
appeared in the literature. In this work, based on our recent exact solution to
an effective eight-dimensional matrix Hamiltonian for the molecular ground
state, we present analytic expressions for the stereochemical properties of OH.
Our results require the solution of algebraic equations only, agree well with
the aforementioned fully numerical calculations, provide compact expressions
for simple field geometries, allow ready access to relatively unexplored
parameter space, and yield straightforwardly higher moments of the molecular
axis distribution.Comment: 8 pages, 9 figure
Options for Human Capital Acquisition
An \u27options\u27 view of human capital acquisition explains value creation through timedeferred, sequential, path-dependent investment choices and addresses gaps in the resourcebased theory explanation of the relationship between human resources and competitive advantage. Firms will invest in options for human capital, using alternative employment arrangements like temporary/contractual/part-time workers and internships, or by outsourcing the work, when uncertainty associated with human capital is high and investments in human capital are largely irreversible. We discuss various options for skills and employees, two interrelated components of human capital. These are flexibility options, options to wait or defer, options to abandon, learning options, and switching options. The opportunity cost of not having options is quantifiable, which makes the real options approach valuable for strategic HRM decisions
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