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The nonreciprocity between two signal fields is regarded as a key function in future quantum networks and modern communication technologies. Here, we theoretically propose a scheme of nonreciprocal devices between signal fields in two different arbitrarily frequency domains in a hybrid cavity opto-electromechanical system. The model consists of a microwave cavity and an optical cavity, respectively, coupled with two different mechanical oscillators, which are coupled together by the tunable Coulomb interaction and driven by the external electrical fields. We study the nonreciprocal response between two different frequency fields. Nonreciprocal transmission is based on multichannel quantum interference to break time-reversal symmetry. The perfect nonreciprocity is shown in the certain conditions. By adjusting the Coulomb interaction, the phase differences, and strength of the electrically driven fields on the mechanical oscillators, we find that nonreciprocity can be modulated and even transformed into perfect nonreciprocity and reciprocity. These results provide a new insight into the design of nonreciprocal devices and present the potential applications in quantum information processing and quantum networks. [ABSTRACT FROM AUTHOR]

We theoretically study the nonlinear optical phenomena including optical stability state and four-wave mixing (FWM) process in a hybrid opto-electromechanical system with the cross-Kerr (CK) effect. The hybrid system consists of an optomechanical cavity in which the cross-Kerr (CK) effect and Coulomb interaction are simultaneously introduced by the CK medium and the mechanical resonator capacitively coupling to an external circuit, respectively. The CK interaction induces a tristability behavior of the mean intracavity photon number, which can be modulated by the strength of the CK effect and electrically controlled by the voltage on the capacitor. In addition, we give the effects of the optomechanical, CK, and Coulomb coupling strengths on the FWM of the output field. The results show that the voltage can be employed to electrically engineer the optical nonlinear phenomena. [ABSTRACT FROM AUTHOR]

The future quantum networks will require reversible coherent conversion and modulation between microwave and optical photons to link the quantum information-processing ability of microwave and long-distance distribution ability of optical photons. Here, we present a scheme of bi-directional phase controllable four-wave mixing (FWM) between microwave and optical fields in the hybrid opto-electromechanical system. As an intermediate interface, a nanomechanical resonator optomechanically couples both optomechanical cavities in the optical and microwave frequency domains by the radiation pressure forces. We can find the four peaks of FWM, study the effects of the phases of the driven fields on the total, absolute, and cross correlation FWMs, and achieve the laws of phase control FWM based on quantum interference. In particular, we believe that such a hybrid opto- and electro-mechanical device incorporating highly coherent and compact mechanical elements on a chip has some potential functions for electro-optic modulation. We expect that such a modulator will have a broad range of applications including in optical communications and further quantum networks. [ABSTRACT FROM AUTHOR]

Black thermal control blankets have been widely used in spacecraft for eliminating stray light around high-resolution optical instruments. However, the limited absorption in visible light range, the fast degradation upon hyperthermal atomic oxygen (AO) in low Earth orbit (LEO), and the poor adhesion of black coatings with substrate confined their applications into board solar spectrum and multi-layer interface engineering. In this work, a nanocomposite polyimide film containing a trisilanolphenyl POSS, a dye of solvent black 34, and a carbon black of CABOT M800 has been designed. With an ingredient of 20 wt% POSS, 5 wt% dye, and 10 wt% carbon black, the nanocomposite polyimide film PPIBC10 exhibited an ultra-low transmittance near zero in the range 200–2000 nm, a low reflectance below 5% in UV range and below 2% in VIS-IR range, and a low erosion yield of 0.49 ± 0.11 × 10−24 cm3 atom−1 upon a 2.27 × 1020 atoms cm−2 hyperthermal AO exposure, with an absorptance of 0.983, an emissivity of 0.86, and a coefficient of thermal expansion of 20 ppm oC−1. SEM and XPS analysis indicated that a uniform SiO x passivating network was formed on surface upon the hyperthermal AO exposure. The tensile strength decreased with increasing additives, and kept stable upon the AO exposure, for there was only sub-micrometer in erosion depth. The thermal expansion coefficients of the nanocomposite films are comparable to that of Kapton, which benefits interface engineering. The small granularity of tens of micrometers and good solubility in poly(amic acid) of additives POSS, dye, and carbon black benefit potential manufacture. This study suggests an ultra-black AO durable polyimide film for potential applications in LEO. Image 1 • A nanocomposite polyimide film was designed with additives of a POSS, a dye, and a carbon black in poly(amic acid). • Bulk-phase black dye and carbon black reinforcements for ultra-low transmittance and reflectance in solar spectrum. • Bulk-phase POSS reinforcement for atomic oxygen resistance. • Comparable coefficient of thermal expansion to Kapton. • Small-granularity and soluble additives in polar solvent. [ABSTRACT FROM AUTHOR]

Photon blockade (PB) is an important quantum phenomenon in cavity quantum electrodynamics (QED). Here, we investigate the PB effect in the simplest cavity QED systems (one cavity containing first a single atom and then two atoms), where only the atoms are weakly driven. Via the analytical calculation and numerical simulation, we show that the strong PB can be generated even with the weak-coupling regime at the total resonance. This blockade is ascribed to the two-photon absorption, which is fundamentally different from the conventional and unconventional blockade mechanisms. Therefore, our study provides an alternative approach to produce the PB in the atom-driven cavity QED system.