We describe a fast quantum computer based on optically controlled electron spins in charged quantum dots that are coupled to microcavities. This scheme uses broadband optical pulses to rotate electron spins and provide the clock signal to the system. Nonlocal two-qubit gates are performed by phase shifts induced by electron spins on laser pulses propagating along a shared waveguide. Numerical s...

Physarum polycephalum is a macroscopic single celled plasmodial slime mould. We employ plasmodial phototactic responses to construct laboratory prototypes of NOT and NAND logical gates with electrical inputs/outputs and optical coupling; the slime mould plays dual roles of computing device and electrical conductor. Slime mould logical gates are fault tolerant and resettable. The results present...

We examine three possible implementations of nondeterministic linear optical controlled NOT gates with a view to an in-principle demonstration in the near future. To this end we consider demonstrating the gates using currently available sources, such as spontaneous parametric down conversion and coherent states, and current detectors only able to distinguish between zero and many photons. The d...

This research paper is about advancement in Optical Computing an emerging field of computer design and hardware with very fast speed and performances. The optical Computing (also known as Photonic computing) is a technique based on photons of visible light or infrared region rather than Electrons flowing in electric current which are used to perform digital Computations using electronic logic g...

All-optical logic gates have proven their significance in the digital world for implementation of high-speed computations. We propose herein a novel structure an all-optical AND gate using concept power combiner based on Y-shaped metal–insulator–metal waveguide with 4 µm × 7 footprint. This design works principle linear interference. The insertion loss and extinction ratio are given as 0.165 14...

Universal quantum gates lie at the heart of designing computer. Here two compact circuits for implementing post-selected controlled-phase-flip (CPF) gate and Toffoli with linear optics are constructed assisted by one single photons, respectively. The current existing maximum success probability 1/4 optical CPF is achieved resorting to an ancillary photon rather than entangled pair or photons. R...

Dispersion, as the characteristic variation of refractive index with wavelength, is more pronounced, where the wavelength is approaching to the absorption band. In ultra-optical glasses, the nonlinear refractive index, concerning to the light intensity dependent phenomenon, becomes considerable. Here, two ultra-optical property glass systems; TiO2-Bi2O3-PbO (TBP...