Quantum full adders play a key role in the design of quantum computers.The efficiency of a quantum adder directly determines the speed of the quantum computer,and its complexity is closely related to the difficulty an...Quantum full adders play a key role in the design of quantum computers.The efficiency of a quantum adder directly determines the speed of the quantum computer,and its complexity is closely related to the difficulty and the cost of building a quantum computer.The existed full adder based on R gate is a great design but it is not suitable to construct a quantum multiplier.We show the quantum legitimacy of some common reversible gates,then use R gate to propose a new design of a quantum full adder.We utilize the new designed quantum full adder to optimize the quantum multiplier which is based on R gate.It is shown that the new designed one can be optimized by a local optimization rule so that it will have lower quantum cost than before.展开更多
The authors present an analysis of the fault tolerant properties and the effects of temperature on an exclusive OR (XOR) gate and a full adder device implemented using quantum-dot cellular automata (QCA) structures. A...The authors present an analysis of the fault tolerant properties and the effects of temperature on an exclusive OR (XOR) gate and a full adder device implemented using quantum-dot cellular automata (QCA) structures. A Hubbard-type Hamiltonian and the Inter-cellular Hartree approximation have been used for modeling, and a uniform random distribution has been implemented for the simulated dot displacements within cells. We have shown characteristic features of all four possible input configurations for the XOR device. The device performance degrades significantly as the magnitude of defects and the temperature increase. Our results show that the fault-tolerant characteristics of an XOR device are highly dependent on the input configurations. The input signal that travels through the wire crossing (also called a crossover) in the central part of the device weakens the signal significantly. The presence of multiple wire crossings in the full adder design has a major impact on the functionality of the device. Even at absolute zero temperature, the effect of the dot displacement defect is very significant. We have observed that the breakdown characteristic is much more pronounced in the full adder than in any other devices under investigation.展开更多
量子全加器是量子计算机的基本单元,为了减少能耗,降低构造成本及物理实现难度,本文提出一种新型 n 位量子全加器,使用 3n 个CNOT(Controlled NOT)门和 2n -1个Toffoli门实现 n 位量子加减法,采用超前进位方式,不含进位输入,通过最高溢...量子全加器是量子计算机的基本单元,为了减少能耗,降低构造成本及物理实现难度,本文提出一种新型 n 位量子全加器,使用 3n 个CNOT(Controlled NOT)门和 2n -1个Toffoli门实现 n 位量子加减法,采用超前进位方式,不含进位输入,通过最高溢出标志位判断加法的进位和减法的正负号,标志位不参与高低位计算,不增加电路延时,适合 n 位量子并行计算.随机生成4、8、16和32位数分别进行加减仿真操作,验证了全加器的正确性.该全加器量子代价较低,结构简单,有利于提高集成电路规模和集成度.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant No.11861031).
文摘Quantum full adders play a key role in the design of quantum computers.The efficiency of a quantum adder directly determines the speed of the quantum computer,and its complexity is closely related to the difficulty and the cost of building a quantum computer.The existed full adder based on R gate is a great design but it is not suitable to construct a quantum multiplier.We show the quantum legitimacy of some common reversible gates,then use R gate to propose a new design of a quantum full adder.We utilize the new designed quantum full adder to optimize the quantum multiplier which is based on R gate.It is shown that the new designed one can be optimized by a local optimization rule so that it will have lower quantum cost than before.
文摘The authors present an analysis of the fault tolerant properties and the effects of temperature on an exclusive OR (XOR) gate and a full adder device implemented using quantum-dot cellular automata (QCA) structures. A Hubbard-type Hamiltonian and the Inter-cellular Hartree approximation have been used for modeling, and a uniform random distribution has been implemented for the simulated dot displacements within cells. We have shown characteristic features of all four possible input configurations for the XOR device. The device performance degrades significantly as the magnitude of defects and the temperature increase. Our results show that the fault-tolerant characteristics of an XOR device are highly dependent on the input configurations. The input signal that travels through the wire crossing (also called a crossover) in the central part of the device weakens the signal significantly. The presence of multiple wire crossings in the full adder design has a major impact on the functionality of the device. Even at absolute zero temperature, the effect of the dot displacement defect is very significant. We have observed that the breakdown characteristic is much more pronounced in the full adder than in any other devices under investigation.
文摘量子全加器是量子计算机的基本单元,为了减少能耗,降低构造成本及物理实现难度,本文提出一种新型 n 位量子全加器,使用 3n 个CNOT(Controlled NOT)门和 2n -1个Toffoli门实现 n 位量子加减法,采用超前进位方式,不含进位输入,通过最高溢出标志位判断加法的进位和减法的正负号,标志位不参与高低位计算,不增加电路延时,适合 n 位量子并行计算.随机生成4、8、16和32位数分别进行加减仿真操作,验证了全加器的正确性.该全加器量子代价较低,结构简单,有利于提高集成电路规模和集成度.
基金Supported by the State Key Development Program for Basic Research of China(2006CB716204)by the International Corpora-tion Project from the Education Department of China 20060360563)the Key Laboratory of Advanced Photonic and Electronic Materials of Jiangsu Province(BM2003202)
