An Alternative Scheme of Quantum Optical Superfast Tristate CNOT Gate Using Frequency Encoding Principle of Light with Semiconductor Optical Amplifier

Abstract

AbstractPhoton is established as a strong and promising candidate in all-optical signal processing and superfast computing. Again, it is found that photon has a successful approach to be used as a quantum mechanical particle. For this reason, it is used as a carrier of information in optical systems instead of electrons in electronic systems. All-optical quantum systems can provide very high speed, secured and noise free communication and computation. Over the last few decades, several all-optical logic processors, algebraic processors, logic gates and their integrated systems are developed by many researchers. All-optical quantum logic gates with qubit data are the basic building block of an optical quantum computer. In quantum computation, qubits or quantum bits are the quantum analogue of classical boolean bits and are used to store information. Several popular encoding techniques (like phase encoding, frequency encoding, intensity encoding, polarization encoding etc.) are used to develop the qubits. Here, in this paper, the gate matrix for quantum optical tristate CNOT logic gate is developed for the first time with a frequency encoding technique. Quantum optical CNOT gate is one of the most important logic gates in the logic family that is extensively used for performing information processing task in optical systems. Tristate-based optical logic operations are proved to increase the data handling capacity. Also, the speed of different types of optical logic operations can be increased with tristate-based optical logic systems. Introduction of contradiction state is another advantage of tristate logic systems. Frequency encoding principle is the best way to encode tristate, quaternary state and multivalued logic states. In the article, the authors have developed a proper truth table and gate matrix of frequency encoded tristate CNOT gate. The all-optical scheme for tristate CNOT gate can be implemented with semiconductor optical amplifier (SOA)-based optical switches. At the same time advantages of quantum optical operations are exploited.KeywordsSemiconductor optical amplifierTristate logicFrequency encoding principle