1.1.2 未来方向

We’ve looked at some of the history and present status of quantum computation andquantum information. What of the future? What can quantum computation and quantum information offer to science, to technology, and to humanity? What benefits doesquantum computation and quantum information confer upon its parent fields of computerscience, information theory, and physics? What are the key open problems of quantumcomputation and quantum information? We will make a few very brief remarks aboutthese overarching questions before moving onto more detailed investigations.

我们已经看了一些量子计算和量子信息的历史和现状。未来会怎样?量子计算和量子信息能给科学、技术和人类带来什么?量子计算和量子信息给计算机科学、信息理论和物理学的母体领域带来了什么好处?量子计算和量子信息的关键开放问题是什么?在进行更详细的调查之前，我们将对这些总体问题做一些非常简短的评论。

Quantum computation and quantum information has taught us to think physicallyabout computation, and we have discovered that this approach yields many new andexciting capabilities for information processing and communication. Computer scientistsand information theorists have been gifted with a new and rich paradigm for exploration. Indeed, in the broadest terms we have learned that any physical theory, not justquantum mechanics, may be used as the basis for a theory of information processingand communication. The fruits of these explorations may one day result in informationprocessing devices with capabilities far beyond today’s computing and communicationssystems, with concomitant benefits and drawbacks for society as a whole.

量子计算和量子信息教会了我们从物理角度思考计算，我们发现这种方法在信息处理和通信方面产生了许多令人兴奋的新能力。计算机科学家和信息理论家被赋予了一种新的、丰富的探索范式。事实上，从广义上讲，我们已经了解到，任何物理理论，不仅仅是量子力学，都可以作为信息处理和通信理论的基础。这些探索的成果可能有一天会导致信息处理设备的能力远远超过今天的计算和通信系统，为整个社会带来好处和缺点。

Quantum computation and quantum information certainly offer challenges aplentyto physicists, but it is perhaps a little subtle what quantum computation and quantum information offers to physics in the long term. We believe that just as we have learned tothink physically about computation, we can also learn to think computationally aboutphysics. Whereas physics has traditionally been a discipline focused on understanding ‘elementary’ objects and simple systems, many interesting aspects of Nature arise onlywhen things become larger and more complicated. Chemistry and engineering deal withsuch complexity to some extent, but most often in a rather ad hoc fashion. One ofthe messages of quantum computation and information is that new tools are availablefor traversing the gulf between the small and the relatively complex: computation andalgorithms provide systematic means for constructing and understanding such systems.Applying ideas from these fields is already beginning to yield new insights into physics. It is our hope that this perspective will blossom in years to come into a fruitful way ofunderstanding all aspects of physics.

量子计算和量子信息无疑给物理学家带来了很多挑战，但从长远来看，量子计算和量子信息给物理学带来的影响可能有点微妙。我们相信，就像我们学会了用物理的方式思考计算一样，我们也可以学会用计算的方式思考物理。传统上，物理学是一门专注于理解“基本”物体和简单系统的学科，而只有当事物变得更大、更复杂时，自然界的许多有趣方面才会出现。化学和工程在某种程度上处理这种复杂性，但大多数情况下是以一种相当特别的方式。量子计算和信息的一个信息是，新的工具可以用来跨越小和相对复杂之间的鸿沟:计算和算法为构建和理解这样的系统提供了系统的手段。应用这些领域的想法已经开始产生对物理学的新见解。我们希望，这一观点将在未来几年开花结果，成为理解物理学各个方面的一种富有成效的方式。

We’ve briefly examined some of the key motivations and ideas underlying quantumcomputation and quantum information. Over the remaining sections of this chapter wegive a more technical but still accessible introduction to these motivations and ideas, withthe hope of giving you a bird’s-eye view of the field as it is presently poised.

我们简要地考察了量子计算和量子信息背后的一些关键动机和思想。在本章的其余部分中，我们将对这些动机和想法进行更技术性的介绍，但仍然容易理解，希望能让你对这个领域有一个鸟瞰图，因为它目前已经准备好了。