No-cloning theorem

Since no-cloning theorem has a profound influence on quantum information , it becomes important to study quantum cloning machine ( QCM ) .

由于量子不可克隆原理对量子信息和量子计算产生了深刻的影响，研究量子态的克隆及其相关问题变得非常重要。

Quantum information can be interpreted as a generalization for all manners of operations that might be related to information processing using quantum mechanics . It encompasses subjects such as quantum computation , quantum teleportation , the no-cloning theorem and so on .

量子信息可以被解释为与利用量子力学进行信息处理有关的所有操作方式的概括，包括量子计算、量子隐形传态、不可克隆原理等。

Quantum system has some unique attributes : the Heisenberg uncertainty principle and no-cloning theorem .

量子系统具有独特属性：测不准性和不可克隆性。

We review the quantum no-cloning theorem and the principle of the quantum copying machine .

本文主要介绍了量子不可克隆定理的物理内容以及量子复制机的基本原理。

Secondly , the measurement of the degree of quantum entanglement , quantum no-cloning theorem , and manipulation of quantum entanglement are introduced .

给出了几类常见的纠缠态，量子纠缠态的度量，量子非克隆定理以及几种主要的纠缠操作；

Here , the basic theorem of the security of quantum cryptography is no-cloning theorem , which forbids cloning an unknown state perfectly .

其中量子密码安全性的基础是量子不可克隆原理。

Such as the establishment of the safe absolute quantum code system , based on the quantum no-cloning theorem which forbids the quantum information be copied as the classical information .

又如，量子不可克隆定理使得量子信息不能像经典信息那样可以被任意复制，这使得人们能够建立起绝对安全的量子密码系统。

Different from traditional cryptography which based on the assumed difficulty of mathematical problems , the security of quantum cryptography is based on Heisenberg uncertainty principle and quantum no-cloning theorem .

不同于以数学问题为基础的传统密码体制，量子密码学的安全性是由海森堡测不准原理以及单量子不可克隆定理来保证的。

It is impossible to copy ( or clone ) an unknown quantum state perfectly . This is one of the basic rules governing the quantum physics , and that is no-cloning theorem .

对一个未知的量子态精确的复制（或克隆）是不可能的，这是支配量子体系的基本原理之一，即量子不可克隆定理。

The output state of quantum copying machine based on the quantum no-cloning theorem depends on the input state . It works well for coping some states , but for the other states it works badly .

在量子不可克隆基础上的量子复制机输出状态依赖于输入状态，对一些量子态复制的很好，对一些量子态复制的较差。

According to the basic principles of quantum mechanics including quantum no-cloning theorem , the Heisenberg uncertainty principle and measurement-collapse theory , any eavesdropping on the key can be found by legitimate communication parties .

量子力学的基本原理：量子不可克隆定理，海森堡不确定性原理和测量塌缩理论决定了任何对密钥的窃听都可以被合法通信方发现。

It has , in quantum information processing , many traits which do not exist in classical information processing for different rules between quantum theory and classical physics , such as coherent superposition property of quantum state and no-cloning theorem .

由于量子力学的规律不同于经典物理学，就导致了量子信息过程带有许多经典信息过程所不具备的特征。比如，量子态的相干叠加性，使得量子信息能够以并行的方式进行演化。

For quantum computer , because of the no-cloning theorem and the linearity of the Hilbert space , an arbitrary unknown quantum state is not copied exactly . Therefore much more attention has been turned to approximate quantum cloning .

而对于量子计算机，由于量子不可克隆定理的局限，精确地拷贝任意未知量子态是不能实现的，因此人们要将更多的精力放在对近似的量子克隆理论的研究。