The Computer Journal Advance Access originally published online on July 12, 2007
The Computer Journal 2008 51(2):207-215; doi:10.1093/comjnl/bxm042
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Bi-Directional Synthesis of 4-Bit Reversible Circuits
1 School of Computer Science and Engineering, University of Electronic Science and Technology of China, Chengdu, Sichuan 610054, China
2 Department of Electrical and Computer Engineering, Portland State University, Portland, OR 97207, USA
3 Synplicity Inc., Sunnyvale, CA 94086, USA
* Corresponding author: william_hung{at}alumni.utexas.net
Received 12 March 2006; revised 29 March 2007
Reversible circuits play an important role in quantum computing, which is one of the most promising emerging technologies. In this paper, we investigate the problem of optimally synthesizing 4-bit reversible circuits. We present an enhanced bi-directional synthesis approach. Owing to the exponential nature of the memory and run-time complexity, all existing methods can only perform four steps for the Controlled-Not gate NOT gate, and Peres gate library. Our novel method can achieve 12 steps. As a result, we augment the number of circuits that can optimally be synthesized by over 5 x 106 times. We synthesized 1000 random 4-bit reversible circuits. The statistical analysis result supports our estimation. The quantum cost of our result is also better than the quantum cost of other approaches. The promising experimental results demonstrate the effectiveness of our approach.
Key Words: reversible logic quantum circuits minimization algorithm