Enhancement of steady-state bosonic squeezing and entanglement in a dissipative optomechanical system

We systematically study the influence of amplitude modulation on the steady-state bosonic squeezing and entanglement in a dissipative three-mode optomechanical system, where a vibrational mode of the membrane is coupled to the left and right cavity modes via the radiation pressure. Numerical simulation results show that the steady-state bosonic squeezing and entanglement can be significantly enhanced by periodically modulated external laser driving either or both ends of the cavity. Remarkably, the fact that as long as one periodically modulated external laser driving either end of the cavities is sufficient to enhance the squeezing and entanglement is convenient for actual experiment, whose cost is that required modulation period number for achieving system stability is more. In addition, we numerically confirm the analytical prediction for optimal modulation frequency and discuss the corresponding physical mechanism.Comment: 25 pages, 8 figures, accepted for publication in Optics Expres

Electronic transport in quasi-one-dimensional arrays of gold nanocrystals

We report on the fabrication and current-voltage (IV) characteristics of very narrow, strip-like arrays of metal nanoparticles. The arrays were formed from gold nanocrystals self-assembled between in-plane electrodes. Local cross-linking of the ligands by exposure to a focused electron beam and subsequent removal of the unexposed regions produced arrays as narrow as four particles wide and sixty particles long, with high degree of structural ordering. Remarkably, even for such quasi-one-dimensional strips, we find nonlinear, power-law IV characteristics similar to that of much wider two-dimensional (2D) arrays. However, in contrast to the robust behavior of 2D arrays, the shape of the IV characteristics is much more sensitive to temperature changes and temperature cycling. Furthermore, at low temperatures we observe pronounced two-level current fluctuations, indicative of discrete rearrangements in the current paths. We associate this behavior with the inherent high sensitivity of single electron tunneling to the polarization caused by the quenched offset charges in the underlying substrate.Comment: 5 pages, 4 figure

Carrier-envelope phase dependence of nonsequential double ionization of H2 by few-cycle laser pulses

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