We study the unitary time evolution of a simple quantum Hamiltonian describing two harmonic oscillators coupled via a three-level system. The latter acts as an engine transferring energy from one oscillator to the other and is driven in a cyclic manner by time-dependent external fields. The S-matrix (scattering matrix) of the cycle is obtained in analytic form. The total number of quanta contai...

In this paper we work in perturbative Quantum Gravity coupled to Scalar Matter at tree level and we introduce a new effective model in analogy with the Fermi theory of weak interaction and in relation with a previous work where we have studied only the gravity and its selfinteraction. This is an extension of the I.T.B model (Intermediate-Tensor-Boson) for gravity also to gravitational interacti...

Linear optical networks are devices that turn classical incident modes by a linear transformation into outgoing ones. In general, the quantum version of such transformations may mix annihilation and creation operators. We derive a simple formula for the effective Hamiltonian of a general linear quantum network, if such a Hamiltonian exists. Otherwise we show how the scattering matrix of the net...

Water deficiency is one of the most important environmental stresses that limit plant growth and crop production. Measurement of chlorophyll fluorescence parameters is considered as an important indicator to evaluate the photosynthetic apparatus. In the present study, the effects of regulated water deficit, investigated in four water-regimes in pistachio orchard with 12-year-old trees of Akbari...

We discuss the tuning of the anisotropic clover action and Symanzik-improved gauge action in lattice perturbation theory. The fermion action is constructed from stout-smeared spatial links, which complicates the calculation considerably. In addition, the full quark-mass dependence of the action parameters is included in this study. We present results for the fermion and gauge aspect ratios for ...

We study string propagation in a spacetime with positive cosmological constant, which includes a circle whose radius approaches a finite value as |t| → ∞, and goes to zero at t = 0. Near this cosmological singularity, the spacetime looks like IR/ZZ. In string theory, this spacetime must be extended by including four additional regions, two of which are compact. The other two introduce new asymp...

We consider a model for the decay B 0 → ρ 0 γ in which the short-distance amplitude determined by the Hamiltonian describing b → dγ is combined with a typical long-distance contribution B 0 → D + D − → ρ 0 γ. The latter possesses a significant dynamical phase which induces a CP-violating asymmetry A CP , as well as an important modification of the Stokes vector of the photon.

In this paper, quantum mechanical effects on nanoscale MOSFET devices are investigated through compact physical models. These models cover quantum mechanical influences on device parameters including long-channel threshold voltage shift, gate capacitance degradation, deteriorated short channel effects and sub-threshold slope. In-depth understanding of device characteristic modification brought ...