2,822 research outputs found
Anderson-type model for a molecule adsorbed on a metal surface
We investigate a modified Anderson model to study the local density of states
(LDOS) of a molecular wire adsorbed on a metal. Using a self-consistent
mean-field type approach we find an exponential decay of the LDOS along the
molecule. A repulsive on-site interaction on the molecule suppresses the
tunneling and decreases the characteristic decay length.Comment: 7 pages (using europhys.sty), 5 EPS figures, To appear in Europhys.
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Coupling Circuit Resonators Among Themselves and To Nitrogen-Vacancy Centers in Diamond
We propose a scheme to couple NV centers in diamond through coplanar
waveguide resonators. The central conductor of the resonator is split into
several pieces which are coupled strongly with each other via simple capacitive
junctions or superconducting Josephson junctions. The NV centers are then put
at the junctions. The discontinuity at the junctions induces a large local
magnetic field, with which the NV centers are strongly coupled to the circuit
resonator. The coupling strength between the resonator and the NV center is
of order of --30\unit{MHz}.Comment: 4 pages; 3 figures; several typos corrected; figure 1 regenerate
Infantile mortality and fertility decisions in a stochastic environment
We analyze the effect of stochastic survival of children on fertility decision in a dynastic utility model where saving, so to speak, can only be made through having children, the number of which is an endogenous decision to the household. In our stochastic framework where the rate of population change undergoes a process of Brownian motion, the probability distribution of the steady state is well determined, and saving via the number of offsprings incorporates a precautionary component. Any health care assistance proposed to reduce the variance of the Brownian process, for example, to reduce the risk of premature infantile mortality, would have a negative effect on the fertility rate and a positive effect on the per capita consumption in the long run.Brownian motion
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