EXPLOITING RELATIVITY FOR QUANTUM INFORMATION THEORY

我的研究计划是研究如何利用相对论效应来改善量子信息任务，这是一个在今天已经具有巨大技术重要性的关键课题，在未来几十年将更加重要。这些研究的Vantage在于，世界从根本上既是量子的，也是相对论的，这些事实对于设计绝对安全的通信设备和量子计算机非常有用，这些通信设备和量子计算机可以快速执行困难的计算任务，这些任务压倒了任何经典的计算机。事实上，令人印象深刻的技术成就和承诺已经来自于认真对待物质的量子方面：量子密码学和通信近年来已经成为技术现实，但量子计算机的实际构建仍然需要更好地理解如何有效地存储，操纵和读取信息，而不会受到环境的巨大干扰。将相对论引入方程，从根本上改变了整个游戏，正如我在一系列研究论文中所展示的那样，其中一篇文章在一篇普遍可访问的科学文章中突出了我的工作（Cho，Science 2005）。我建议将这一令人兴奋的理论研究方向推向量子信息理论中的相对论效应可以在技术上得到利用的地步。相对论不仅产生定量的修正，而且在许多用于在实验室中实现量子信息任务的物理系统的定性行为中起着主导作用。任何涉及光的系统都提供了一个典型的例子，无论是用于传输还是操纵量子信息。光量子，即所谓的光子，不存在非相对论近似，因为它们总是以光速传播。虽然相对论量子理论，通常被称为量子场论，是基础粒子物理学中一个非常好的研究课题，但量子信息理论的研究选择性地集中在那些可以在没有相对论的情况下研究的方面。因此，量子信息理论的意外障碍（如量子纠缠的相对论退化）和无法想象的可能性（如改进的量子密码学和超灵敏的量子测量设备）都没有被注意到。在过去的几年里，我和同事们一起提供了这些见解的相关性，其他研究人员认可并建立在我的工作基础上的工作量证明了这一点。事实上，我的研究的影响超出了纯粹的量子信息理论，并在宇宙学和黑洞物理学的基础问题的应用程序已经发现。我建议在我的奖学金期间完成的研究旨在提供相对论量子信息理论的基础，理论和技术方面的全面答案，利用和建设迄今为止所获得的有趣的结果。我的总体愿望和愿景是最终为量子信息理论领域的关键问题提供具体的解决方案。

My research programme is the study of how relativistic effects can be exploited to improve quantum information tasks, a key topic of immense technological importance already today and more so for the next decades. The vantage point of these investigations is that the world is fundamentally both quantum and relativistic, and that these facts are immensely useful for the design of communication devices that are absolutely safe from eavesdropping, and of quantum computers that can quickly perform difficult computational tasks which overwhelm any classically imaginable computer. Indeed, impressive technological achievements and promises have already been derived from taking seriously solely the quantum aspects of matter: quantum cryptography and communication have become a technical reality in recent years, but the practical construction of a quantum computer still requires to understand better how to efficiently store, manipulate and read information, without prohibitively large disturbances from the environment. Throwing relativity into the equation fundamentally changes the entire game, as I could show in a series of research papers, one of which was featured in a generally accessible Science article highlighting my work (Cho, Science 2005). I propose to push this exciting line of theoretical research to the point where relativistic effects in quantum information theory can be exploited technologically.Far from yielding only quantitative corrections, relativity plays a dominant role in the qualitative behaviour of many physical systems used to implement quantum information tasks in the laboratory. The prototypical example is provided by any system involving light, be it for the transmission or manipulation of quantum information. There is no such thing as a non-relativistic approximation to light quanta, so-called photons, since these always travel at the speed of light. While relativistic quantum theory, commonly known as quantum field theory, is a very well studied subject in foundational particle physics, research in quantum information theory selectively focused almost exclusively on those aspects one can study without relativity. Thus both unexpected obstacles (such as a relativistic degradation of quantum entanglement) and unimagined possibilities for quantum information theory (such as improved quantum cryptography and hypersensitive quantum measurement devices) have gone unnoticed. The relevance of these insights, which together with co-workers, I afforded over the past few years, are evidenced by the amount of work by other researchers recognizing and building on my work. Indeed, the impact of my research extends beyond pure quantum information theory, and applications to foundational questions in cosmology and black hole physics have been found.The research I propose to complete during my Fellowship aims at providing comprehensive answers to foundational, theoretical and technological aspects of relativistic quantum information theory, exploiting and building on the intriguing results obtained so far. My overall aspiration and vision is to ultimately provide concrete solutions to key problems in the field of quantum information theory.