Adiabatic Switch Research Articles

Soliton formation and dynamics in the quintic nonlinear media with [formula omitted]-invariant harmonic-Gaussian potential

In this paper, we introduce a PT-symmetric harmonic-hyperbolic-Gaussian (HHG) potential in the nonlinear Schrödinger (NLS) equation with quintic nonlinearity. Firstly, we present the critical thresholdless PT-phase symmetry breaking in the linear regime. Secondly, we give both exact and numerical single-/double-hump solitons of the quintic NLS equations with the PT-symmetric HHG potential, and show their stabilities by studying the spectrum stability analysis and direct wave propagations. Finally, we investigate the interactions between the single-/double-hump solitons and the exotic hyperbolic secant function, as well as the adiabatic excitations of the solitons with the operation of an adiabatic switch function. All these obtained results provide a theoretical guidance for the applications of the PT-symmetric theory into diverse areas of physics.

Adiabatic differential voltage switch logic

To diminish the trapped charges in internal nodes of the complex logic adiabatic gate, adiabatic differential voltage switch logic (ADVSL) using capacitance coupling technique is presented. An adiabatic system, based on a relatively small number of complex ADVSL gates, reduces not only dissipation loss, but also the gate count greatly.

0.8 V CMOS adiabatic differential switch logic circuit using bootstrap technique for low-voltage low-power VLSI

A novel 0.8 V CMOS adiabatic differential switch logic (ADSL) circuit using the bootstrap technique for low-voltage low-power VLSI is reported. Using capacitance coupling effects from the bootstrap transistors with the related isolating transistors, this 0.8 VADSL circuit has a 52% smaller propagation delay time, consuming 26% less power as compared to the energy efficient logic circuit.

Time-Dependent Behavior in Arrays of Two Coupled Quantum-Dot Cells

Time-dependent behavior of two kinds of arrays of two coupled quantum-dot cells is examined. Each square cell composed of four quantum dots in the corners contains two electrons and couples with the neighboring cells by Coulomb interactions. The electrons in one cell tend to occupy antipodal dots which results in a cell "polarization". We have investigated the temporal evolution of the polarization of one cell under switch of the polarization of the other cell. Our results demonstrate that, with an adiabatic switch, if two cells are arranged in a line their polarizations will align each other, and if they are arranged in a diagonal way their polarizations will invert each other. However, with an abrupt switch, the above features for the polarizations of two cells can not hold. The reason is that the system does not stay in its ground state. It is pointed out that the energy dissipation should be considered in order to obtain the appropriate solutions.

An adiabatic differential logic for low-power digital systems

A new adiabatic circuit technique called adiabatic differential cascode voltage switch with complementary pass-transistor logic tree (ADCPL) is presented. ADCPL is a dual-rail logic with refatively low gate complexity. It operates from a two-phase nonoverlapping supply clock, power reduction is achieved by recovering the energy in the recover phase of the supply clock. Energy dissipation comparison with other logic circuits is performed, Simulation shows that for a pipelined ADCPL carry lookahead adder, a power reduction of 50%-70% can be achieved over the static complimentary metal oxide semiconductor case within a practical operation frequency range. The results also show that the lower the operating frequency, the larger the energy savings for an ADCPL circuit.

Adiabatic polymer-glass-waveguide all-optical switch

We propose an adiabatic all-optical switch that is composed of an asymmetric Y-branch ion-exchanged glass waveguide with a strip of nonlinear polymer loaded on top of one branch. The properties of nonlinear wave propagation in the device are investigated in detail. By extending the effective-index method to the analysis of nonlinear waveguides, we calculate the nonlinear dispersion curves in successive sections to explain the evolution of normal modes in the device. As the multivalued propagation constants exist in the tapered directional coupler region, the device possesses an abrupt switching behavior and nonreciprocal properties. To demonstrate nonlinear switching behaviors in the Y-branch waveguide further, we employ a beam propagation method to simulate optical-field propagation. The inputs by three different ports are investigated, and the results agree well with the dispersion-curve analysis.

Harmonic generation in ionizing systems by the complex scaled adiabatic-switch method.

An adiabatic-switch method for calculating harmonic generation under intense laser radiation is presented. The adiabatic switch is first applied to nonbound (i.e., ionizing or dissociative) time-periodic Hamiltonians when the energy spectrum is degenerate. Our derivation is based on the use of Floquet theory combined with complex scaling and of a generalized definition of the inner product for non-Hermitian operators. A model potential representing a Xe atom in the presence of a laser field is studied as an example to illustrate the numerical advantages of the present method and its stability.

Time-dependent spectra of colliding atoms in an intense radiation field

The author expresses the time-dependent physical spectrum of any signal as a twofold convolution over frequency and time of the Page-Lampard quasi-spectrum and a smoothing function that is determined by the properties of the spectrometer. This result is applied to the collisional redistribution of intense time-dependent radiation. Without resort to the adiabatic approximation the authors derive a differential equation that determines the time-dependent redistributed spectrum for any given time variation of the incident field. In the special case of adiabatic or sudden switch on the incident radiation he evaluates the approach to the steady state of the fluorescence spectrum of a two-state atom.

Many-electron hopping in semiconductors

Correlated hopping of many electrons in the impurity band of moderately compensated semiconductors at low temperature is studied. The growth of the electric dipole moment of the n-electron cluster after the adiabatic switch on of the electron-phonon interaction and the external electric field is calculated. One- and two-phonon processes are considered. The theory is based on the following assumptions: one-electron states in the impurity band are strongly localized, the motion of each electron is restricted to the hopping between two impurity sites, the Coulomb interaction between electrons in the cluster is strong, and the deformation potential type coupling to phonons is assumed. It is shown that the exchange of virtual phonons during the hopping events results in the renormalization of the transfer matrix elements. The calculation also reveals an interference effect between the contributions of different electrons to the current.