Computer Engineering and Applications ›› 2021, Vol. 57 ›› Issue (19): 112-115.DOI: 10.3778/j.issn.1002-8331.2009-0193

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Design of Improved TR Gate Cascade Quantum Comparator

ZHOU Lin, GUO Bing   

  1. School of Computer Science & Engineering, Sichuan University, Chengdu 610065, China
  • Online:2021-10-01 Published:2021-09-29



  1. 四川大学 计算机科学与技术,成都 610065


The quantum comparator is an important part in the design of quantum algorithms, and it is of great significance to the physical implementation of quantum algorithms. Aiming at the quantum cost and garbage output optimization problem of the comparator, a quantum comparator design scheme with improved TR gate cascade is proposed in three stages. The first stage uses Boolean logic to derive the realization of the scheme and simplify it, the second stage designs a 1?bit quantum comparator; the third stage cascades the comparators and realizes the generality of [n] bit comparators. Iterative derivation proves its correctness. Compared with other documents, this design reduces the quantum cost by nearly 12.6% and saves 47.6% of garbage output. Finally, experimental simulation proves that it can operate normally. Compared with other types of comparators, the quantum cost and garbage output required by the design are significantly reduced, and the structure is simple and easy to implement.

Key words: quantum computing, comparator, reversible logic, quantum cost, garbage output



关键词: 量子计算, 比较器, 可逆逻辑, 量子代价, 垃圾输出