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An NRR/GOR couple electrolyzer was constructed and required only 1.2 V voltage for electrochemical NH3 production in the presence of glycerol.

We present an extended collision model to simulate the dynamics of an open quantum system. In our model, the unit to represent the environment is, instead of a single particle, a block which consists of a number of environment particles. The introduced blocks enable us to study the effects of different strategies of system-environment interactions and states of the blocks on the non-Markovianities. We demonstrate our idea in the Gaussian channels of an all-optical system and derive a necessary and sufficient condition of non-Markovianity for such channels. Moreover, we show the equivalence of our criterion to the non-Markovian quantum jump in the simulation of the pure damping process of a single-mode field. We also show that the non-Markovianity of the channel working in the strategy that the system collides with environmental particles in each block in a certain order will be affected by the size of the block and the embedded entanglement and the effects of heating and squeezing the vacuum environmental state will quantitatively enhance the non-Markovianity.

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We report the observation of multiple laser thresholds in the many-atom cavity QED microlaser. Traveling-wave coupling and a supersonic atom beam are used to create a well-defined atom-cavity interaction. Multiple thresholds are observed as jumps in photon number due to oscillatory gain. Although the number of intra-cavity atoms is large, up to N ∼ 10 3 , the dynamics of the microlaser agree with a single atom theory. This agreement is supported by quantum trajectory simulations of a many-atom microlaser and a semiclassical microlaser theory. We discuss the relation of the microlaser with the micromaser and conventional lasers.The most fundamental model of light-matter interaction at the atomic level consists of a two-level atom coupled to a single mode of the electromagnetic field, e. g. in an optical resonator. For an atom-cavity coupling strength greater than the decay rates of atom and cavity (g ≫ Γ c , Γ a ), an excited atom exchanges energy coherently with the cavity (Rabi oscillation). [1] Atom-resonator interaction is also the domain of laser physics; therefore it may be somewhat surprising that most descriptions of laser operation use an incoherent model involving population densities and Einstein A and B coefficients. Such a model applies due to gain medium broadening, laser field nonuniformity, and other statistical effects [2].The microlaser is to our knowledge the first laser in which coherent Rabi oscillation is explicitly reflected in the dynamics of the laser. A controlled atom-cavity interaction and absence of strong statistical averaging leads to behavior foreign to conventional lasers. In this paper we report the most dramatic of these effects, the existence of multiple laser thresholds.The microlaser is the optical analogue of the micromaser [3], in which a similar bistable behavior has been observed for a single atom in the cavity [4]. The most significant differences between the two experiments are: (i) a large number of atoms is present, (ii) optical frequencies allow direct detection of generated light, and (iii) the number of thermal photons at optical frequencies is negligible.An earlier version of the microlaser experiment [5] was shown to exhibit laser action with an intracavity atom number N on the order of 1. In the current setup, N ≫ 1; remarkably, the many-atom system exhibits very similar behavior to that predicted from a single atom theory. This is supported by quantum trajectory simulations and may be explained by a semiclassical theory ([6], [7]).The experiment is illustrated in Fig. 1. A supersonic beam of 138 Ba atoms passes through the TEM 00 mode of a high-finesse optical cavity (symmetric near-planar cavity, mirror separation L ≈ 0.94 mm, mirror radius of curvature r 0 = 10 cm, finesse F ≈ 9.0 × 10 5 .) The mirror separation and finesse were determined by measurement of transverse mode spacing and cavity ringdown decay time. The background pressure in the vacuum chamber is less than 10 −6 torr. Prior to entering the cavity mode, each atom is excited by a cw pump laser (Co...