The quantum gate array is the natural quantum generalization of acyclic combinational logic " circuit " studied in conventional computational complexity theory . in 1995 , barenco showed that almost any two - bit gate is universal , so building a feasible two - bit logic gate is the first step to engineer a quantum computer . in principle , the quantum bit can be carried by any two states system 在眾多的量子計(jì)算機(jī)模型中目前討論最廣泛的是量子計(jì)算機(jī)門組網(wǎng)絡(luò)模型,量子計(jì)算機(jī)門組網(wǎng)絡(luò)模型是經(jīng)典計(jì)算機(jī)門組網(wǎng)絡(luò)結(jié)構(gòu)的量子推廣,它是根基于barenco等人所證明的“一個(gè)兩比特受控操作和對(duì)單比特進(jìn)行任意操作的門可以構(gòu)成一個(gè)‘通用量子邏輯門組’ ”之上的。
Computational complexity theory is a branch of the theory of computation in theoretical computer science and mathematics that focuses on classifying computational problems according to their inherent difficulty, and relating those classes to each other. A computational problem is understood to be a task that is in principle amenable to being solved by a computer, which is equivalent to stating that the problem may be solved by mechanical application of mathematical steps.