International Technology Roadmap for Semiconductors 2003の要求清浄度について － シリコンウエハ表面と雰囲気環境に要求される清浄度, 分析方法の現状について －

We establish a method for exploring the dynamics of molecular quantum-dot cellular automata (QCA) devices by hierarchically combining the techniques of quantum chemistry with the nonequilibrium time-dependent coherence vector formalism. Single QCA molecules are characterized using ab initio quantum chemistry methods. We show how to construct a simple model Hamiltonian for each QCA cell based on parameters extracted from the ab initio calculation. The model Hamiltonian captures well the relevant switching behavior and can then be used to calculate the time-dependent coherence vector, including thermal and nonequilibrium behavior. This enables us to explore dynamic behavior and power dissipation for various QCA devices and circuits.

http://absimage.aps.org/image/MAR08/MWS_MAR08-2007-006221.pdf

Molecular quantum-dot cellular automata--from molecular structure to circuit dynamics

Quantum-dot cellular automata (QCA) is an emerging area of research in reversible computing. It can be used to design nanoscale circuits. In nanocommunication, the detection and correction of errors in a received message is a major factor. Besides, device density and power dissipation are the key issues in the nanocommunication architecture. For the first time, QCA-based designs of the reversible low-power odd parity generator and odd parity checker using the Feynman gate have been achieved in this study. Using the proposed parity generator and parity checker circuit, a nanocommunication architecture is proposed. The detection of errors in the received message during transmission is also explored. The proposed QCA Feynman gate outshines the existing ones in terms of area, cell count, and delay. The quantum costs of the proposed conventional reversible circuits and their QCA layouts are calculated and compared, which establishes that the proposed QCA circuits have very low quantum cost compared to conventional designs. The energy dissipation by the layouts is estimated, which ensures the possibility of QCA nano-device serving as an alternative platform for the implementation of reversible circuits. The stability of the proposed circuits under thermal randomness is analyzed, showing the operational efficiency of the circuits. The simulation results of the proposed design are tested with theoretical values, showing the accuracy of the circuits. The proposed circuits can be used to design more complex low-power nanoscale lossless nanocommunication architecture such as nano-transmitters and nano-receivers.

/pdf/quantum-dot-cellular-automata-based-reversible-low-power-3744ud1l7g.pdf

Quantum-dot cellular automata based reversible low power parity generator and parity checker design for nanocommunication

This study introduces a novel architecture for image steganography using reversible logic based on quantum dot cellular automata (QCA). Feynman gate is used to achieve the reversible encoder and decoder for image steganography. A Nanocommunication circuit for image steganography is shown using proposed encoder/decoder circuit. The proposed QCA circuits have lower quantum cost than traditional designs. It shows the cost effectiveness functionality of the proposed designs. The proposed circuit has 28.33% improvement in terms of area over complementary metal-oxide-semiconductor circuit. To perform image steganography LSB technique is used; signal-to-noise ratio (SNR), peak SNR and mean squared error (MSE) are also computed. The proposed QCA encoder/decoder circuit is suitable for reversible computing. To establish this, the heat energy dissipation by the proposed encoder/decoder circuit is estimated. The estimation shows that the encoder/decoder circuit has very low energy dissipation. Single missing/additional cell-based defect analysis is also explored in this study. Reliability of the circuit is tested against different temperatures. Implementation and testing of the circuit are achieved using QCADesigner tool. MATLAB is used to produce the input to the proposed circuit.

https://ietresearch.onlinelibrary.wiley.com/doi/pdf/10.1049/iet-cds.2015.0245

Reversible logic-based image steganography using quantum dot cellular automata for secure nanocommunication

Quantum dot-cellular automata (QCA) is an emerging nanotechnological archetype and has widespread applications in designing nanoscale reversible circuit for nanocomputing The low power consumption, faster operating speed, and low circuit area of QCA pledge the energy efficient design of logic circuit having high device complexity This paper demonstrates the design of reversible binary to grey and grey to binary code converter based on Feynman gate using QCA for the first time Both the proposed reversible code converter circuits have quantum cost as 2 The conversion of binary to grey code is achieved with only one garbage value and the grey to binary code conversion is achieved without any garbage value The proposed Feynman gate circuit required only 38,880 nm2 areas and three clocking zones The reversible binary to grey circuit required only 92,664 nm2 areas and three clocking zones whereas the reversible grey to binary circuit required only 139,968 nm2 areas and four clocking zones The pro

Reversible Binary to Grey and Grey to Binary Code Converter using QCA

Quantum dot-cellular automata (QCA) emerge as a research area to design nanometre scale logic circuit. In digital logic design, a comparator is the fundamental building block that performs the comparison of two numbers. This paper deals with the design of reversible building block for 1-bit comparator and its implementation in QCA. An improved QCA layout of Feynman gate is also achieved. The QCA Feynman gate is denser and has low delay than the existing circuit. The proposed reversible comparator has quantum cost 9, whereas the QCA reversible comparator has the quantum cost 0.927. The quantum cost based comparison of the proposed QCA reversible comparator with conventional reversible comparator shows the cost effective circuit design in QCA. The simulation result matched the truth table of comparator which approves the functional capability of the proposed QCA layout of comparator. All the proposed layouts dissipate very low power.

Jadav Chandra Das

Papers

Quantum-dot cellular automata based reversible low power parity generator and parity checker design for nanocommunication

Reversible logic-based image steganography using quantum dot cellular automata for secure nanocommunication

Reversible Binary to Grey and Grey to Binary Code Converter using QCA

Reversible Comparator Design Using Quantum Dot-Cellular Automata

Novel low power reversible binary incrementer design using quantum-dot cellular automata