1. Field of the Invention
The invention relates to the technical field of Boolean circuit synthesis and, more particularly, to a method of automatic synthesis of sequential quantum Boolean circuits.
2. Description of Related Art
Due to the discovery of Shor's prime factorization and Grover's fast database search method, quantum computing becomes one of the most rapidly expanding technology fields. To perform quantum method, the required unitary operations should be expressed as a sequence of basic operations which can be implemented by a quantum computer. To implement a quantum computer, quantum Boolean circuits need to be constructed first.
The major differences between conventional circuits and quantum ones are their logic gates and wires. Firstly, conventional circuits are based on AND, OR and NOT gates and quantum Boolean circuits are based on NOT, Controlled-Not and Controlled-Controlled-Not gates (i.e. Toffoli gates). Secondly, the wires in conventional circuits are used to connect components. This is very different in quantum Boolean circuits because wires represent time evolution.
Due to the differences between the conventional circuits and the quantum ones, there is a method to synthesize combinational quantum Boolean circuits based on transformation tables. As in the cited method, any general m-to-n bit combinational Boolean logic can be synthesized by using Toffoli gates. In the meantime, there are many methods proposed for synthesizing the combinational quantum Boolean circuits. However, there are no related works on synthesizing sequential circuit behaviors into quantum Boolean circuits yet. Therefore, it is desirable to provide a method of automatic synthesis of sequential quantum Boolean circuits to mitigate and/or obviate the aforementioned problems.