3,435 research outputs found
On The Design Of Low-Complexity High-Speed Arithmetic Circuits In Quantum-Dot Cellular Automata Nanotechnology
For the last four decades, the implementation of very large-scale integrated systems has largely based on complementary metal-oxide semiconductor (CMOS) technology. However, this technology has reached its physical limitations. Emerging nanoscale technologies such as quantum-dot cellular automata (QCA), single electron tunneling (SET), and tunneling phase logic (TPL) are major candidate for possible replacements of CMOS. These nanotechnologies use majority and/or minority logic and inverters as circuit primitives. In this dissertation, a comprehensive methodology for majority/minority logic networks synthesis is developed. This method is capable of processing any arbitrary multi-output Boolean function to nd its equivalent optimal majority logic network targeting to optimize either the number of gates or levels. The proposed method results in different primary equivalent majority expression networks. However, the most optimized network will be generated as a nal solution. The obtained results for 15 MCNC benchmark circuits show that when the number of majority gates is the rst optimization priority, there is an average reduction of 45.3% in the number of gates and 15.1% in the number of levels. They also show that when the rst priority is the number of levels, an average reduction of 23.5% in the number of levels and 43.1% in the number of gates is possible, compared to the majority AND/OR mapping method. These results are better compared to those obtained from the best existing methods.
In this dissertation, our approach is to exploit QCA technology because of its capability to implement high-density, very high-speed switching and tremendously lowpower integrated systems and is more amenable to digital circuits design. In particular, we have developed algorithms for the QCA designs of various single- and multi-operation arithmetic arrays. Even though, majority/minority logic are the basic units in promising nanotechnologies, an XOR function can be constructed in QCA as a single device. The basic cells of the proposed arrays are developed based on the fundamental logic devices in QCA and a single-layer structure of the three-input XOR function. This process leads to QCA arithmetic circuits with better results in view of dierent aspects such as cell count, area, and latency, compared to their best counterparts. The proposed arrays can be formed in a pipeline manner to perform the arithmetic operations for any number of bits which could be quite valuable while considering the future design of large-scale QCA circuits
Narrow-line phase-locked quantum cascade laser in the 9.2 micron range
We report on the operation of a 50 mW continuous wave quantum cascade laser
(QCL) in the 9.2 micrometer range, phase locked to a single mode CO2 laser with
a tunable frequency offset. The wide free running emission spectrum of the QCL
(3-5 MHz) is strongly narrowed down to the kHz range making it suitable for
high resolution molecular spectroscopy.Comment: 4 page
NOVEL RESOURCE EFFICIENT CIRCUIT DESIGNS FOR REBOOTING COMPUTING
CMOS based computing is reaching its limits. To take computation beyond Moores law (the number of transistors and hence processing power on a chip doubles every 18 months to 3 years) requires research explorations in (i) new materials, devices, and processes, (ii) new architectures and algorithms, (iii) new paradigm of logic bit representation. The focus is on fundamental new ways to compute under the umbrella of rebooting computing such as spintronics, quantum computing, adiabatic and reversible computing. Therefore, this thesis highlights explicitly Quantum computing and Adiabatic logic, two new computing paradigms that come under the umbrella of rebooting computing. Quantum computing is investigated for its promising application in high-performance computing. The first contribution of this thesis is the design of two resource-efficient designs for quantum integer division. The first design is based on non-restoring division algorithm and the second one is based on restoring division algorithm. Both the designs are compared and shown to be superior to the existing work in terms of T-count and T-depth. The proliferation of IoT devices which work on low-power also has drawn interests to the rebooting computing. Hence, the second contribution of this thesis is proving that Adiabatic Logic is a promising candidate for implementation in IoT devices. The adiabatic logic family called Symmetric Pass Gate Adiabatic Logic (SPGAL) is implemented in PRESENT-80 lightweight algorithm. Adiabatic Logic is extended to emerging transistor devices
Design, Construction, Operation and Performance of a Hadron Blind Detector for the PHENIX Experiment
A Hadron Blind Detector (HBD) has been developed, constructed and
successfully operated within the PHENIX detector at RHIC. The HBD is a
Cherenkov detector operated with pure CF4. It has a 50 cm long radiator
directly coupled in a window- less configuration to a readout element
consisting of a triple GEM stack, with a CsI photocathode evaporated on the top
surface of the top GEM and pad readout at the bottom of the stack. This paper
gives a comprehensive account of the construction, operation and in-beam
performance of the detector.Comment: 51 pages, 39 Figures, submitted to Nuclear Instruments and Method
- …