Graphene based quantum information technologies

摩尔定律指出，计算机的处理能力大约每18个月翻一番，然而，当晶体管达到单个原子的大小时，这将不再成立。在这种微观尺度上，量子力学现象发挥着核心作用，不再像大多数当前信息技术（IT）那样是改进构建模块的简单支持。现代量子信息技术（QIT）不是将量子力学行为视为一个问题，而是根据量子物理学的基本定律，将量子力学用于存储，处理和交换信息的新方案。这种额外的自由将使未来的QIT能够执行标准IT无法执行的任务。显然，这为未来的经济发展提供了强有力的理由，例如微软投资创建Station-Q，这是QIT的一个专门研究中心。 QIT的主要挑战之一是在相对短的时间内“信息丢失”，这是半导体和超导量子比特中的短量子相干时间问题。在这里，我们建议通过利用石墨烯在QIT器件中的潜力来克服这些限制。这是一种看似简单的材料--一个碳原子厚--具有高导电性。石墨烯中的相对论电荷载流子预计具有非常长的相干时间，这将允许即使在室温下也可以在电路中的宏观距离上操纵和传输信息。这是在任何其他已知材料中都没有发现的特性。这些相对论性电荷载流子的一个突出特征是在与超导体的界面处的新型电荷转换机制，其自发地提供在镜面对称轨道上行进的空间分离的量子纠缠电子对。纠缠粒子对，即所谓的EPR对，起着特殊的作用，并已被用作基础研究的玩具对象。它们形成了爱因斯坦“幽灵般的远距离相互作用”的核心，但也为未来的应用提供了基础，如安全编码，隐形传态，量子信息技术和量子计算。电子/空穴的固态纠缠器件以前从未被证明过，其利用石墨烯的独特性质的实现是该提议的核心。

Moore's law states that the computer processing power roughly doubles every 18 months, however this will not hold any longer when transistors reach the size of individual atoms. At this microscopic scale, quantum-mechanical phenomena play a central role and are no longer a simple support in improving the building blocks as is the case in most current information technologies (IT). Rather than viewing the quantum-mechanical behaviour as a problem, modern quantum information technology (QIT) uses quantum mechanics for novel schemes of storing, processing and exchanging information according to the fundamental laws of quantum physics. This additional freedom will enable future QIT to perform tasks which are not possible in standard IT. Clearly, this makes a strong case for future economic development as demonstrated for example by the Microsoft investment in creating Station-Q, which is a dedicated research centre in QIT. One of the major challenges in QIT is the "loss of information" in a relatively short time, a problem known as short quantum coherence time in semiconductor and superconducting quantum bits. Here we propose to overcome these limitations by exploiting the potential of graphene in QIT-devices. This is a deceptively simple material -one carbon atom thick- with high electrical conductivity. The relativistic charge carriers in graphene are expected to have an extraordinarily long coherence time which will allow the manipulation and transfer of information over macroscopic distances in a circuit even at room temperature. This is a property which is not found in any other known material. A prominent feature of these relativistic charge carriers is a novel charge conversion mechanism at the interface with superconductors, which spontaneously delivers spatially separated quantum-entangled pairs of electrons travelling on specularly symmetric trajectories. Pairs of entangled particles, so-called EPR pairs, play a special role and have been used as toy objects for fundamental studies. They form the core of Einstein's "spooky interaction at a distance", but also provide the basis of future applications like secure encoding, teleportation, quantum information technology and quantum computation. A solid state entangler device of electrons/holes has never been demonstrated before and its realization exploiting the unique properties of graphene is at the core of this proposal.