Software Enabling Early Quantum Advantage - SEEQA

SEEQA项目是由牛津大学、伦敦大学学院和布里斯托尔大学共同努力的，得到了多家英国量子创业公司和NQCC的支持。目的是让“量子优势”时代早日到来！“优势”意味着拥有真正的工作量子计算机，可以执行任何传统手段都不可能完成的任务，或者执行速度极其缓慢或昂贵的任务。我们会知道，当我们能够解决化学和材料发现等领域不可能完成的任务，或者以接近零浪费的方式解决复杂的资源分配问题时，这个时代已经到来了。尽管量子计算机长期以来一直承诺这种优势，但它尚未实现。原因有很多——部分原因是原型硬件需要更多时间来成熟。但支持量子计算的实际理论需要取得进展，以“降低硬件需要能够达到的门槛”。这就是SEEQA要做的，主要有三个主题：弄清楚如何最好地利用最先进的传统计算能力来帮助早期的量子计算机。主要有两种方式：首先，传统计算机实际上可以帮助运行量子计算机正在执行的任务。这个任务被分解成许多小的量子计算，传统的计算机得到所有的结果，并把它们放在一起决定下一步要做什么。传统计算机可以提供帮助的另一种方式是通过监测量子处理器的错误：为了从来自监测的证据中推断错误的性质，需要做一些侦探工作，而传统计算机需要做这些工作——这被称为解码。提出处理或抑制错误的新方法。如前所述，量子计算机（尤其是早期的）受到“噪声”的影响，这意味着所做的一切都没有什么瑕疵。如果不处理，产生的错误将导致无用的输出。对抗错误有很多想法，但SEEQA将解决新的可能性。特别是，SEEQA将研究两种主要方法之间的接口，以找到新的解决方案：一种方法被称为量子错误缓解（QEM），它可以抑制错误损害，另一种方法被称为量子错误纠正（QEC），它可以完全修复错误，但目前在所需组件数量方面非常昂贵。此外，SEEQA将探索和推进一些处理测量误差的最新和复杂的想法——如果你不能相信量子计算机的输出，你是非常有限的！3. 最后，SEEQA将专注于我们想要执行的架构或协议之间的相互关系，以及可用的硬件架构（包括噪声源和其他缺陷，“拓扑”意味着哪些量子位可以直接“看到”其他量子位的问题，等等）。尽管对此已经有了相当多的了解，但在两个主题(a)“什么算法可以在我的架构上很好地运行？”和(b)“我的算法可以在什么架构上运行？”中仍然存在许多问题。作为所有这些理论研究的基础，检验事物的能力至关重要。SEEQA项目将提供两种条件：首先，在传统计算机上运行的非常高效的软件“假装”是量子计算机——使用众所周知的量子物理定律精确地模拟它们。然而，由于量子态非常复杂，它只能在小型模拟量子计算机上工作。因此，SEEQA也有机会使用真正的量子处理器原型是至关重要的——因为它们类型繁多，所以要尽可能多。幸运的是，SEEQA收到了多封支持信，提供了接近50万英镑的资源，这些资源来自目前正在工作的量子原型的英国先驱硬件公司。他们将为SEEQA提供专家和设备，以帮助我们取得成功。

The project Software Enabling Early Quantum Advantage (SEEQA, pronounced 'seeker') is a joint effort by Oxford, UCL, and Bristol, supported by multiple UK quantum startup companies and NQCC. The aim is to make the era of "quantum advantage" arrive sooner! "Advantage" means having real working quantum computers that can perform tasks that are either impossible, or prohibitively slow or expensive, by any conventional means. We'll know this era has arrived when we can solve otherwise-infeasible tasks in areas such as chemistry and materials discovery or in solving complicated resource allocation problems with near-zero waste. Although quantum computers have long promised this kind of advantage, it has not yet been realised. There are many reasons -- partly it is just that the prototype hardware needs more time to mature. But progress needs to be made in the practical theory to support quantum computing, to 'lower the bar' that the hardware needs to be able to reach. This is what SEEQA will do, in three main themes:1. Figuring out how best to use state-of-the-art conventional computing power to help early quantum computers. There are two main ways: First, the conventional computers can actually help run the task that the quantum computer is performing. The task gets broken up into lots of small quantum computations, and the conventional computer gets all the results and puts them together to decide what to do next. The other way a conventional computer can help is by monitoring the quantum processor for errors: there is some detective work to do in order to infer the nature of the errors from the evidence that comes from monitoring, and a conventional computer needs to do this -- it's called decoding.2. Coming up with new ways in which to handle or suppress errors. As mentioned, quantum computers (especially the early ones) suffer from 'noise' which means little imperfections in everything that is done. If not handled, the resulting errors will lead to useless outputs. There are many ideas for fighting errors, but SEEQA will address new possibilities. In particular, SEEQA will investigate the interface between two major approaches to find new solutions: The approaches are called Quantum Error Mitigation (QEM), which suppresses error damage, and Quantum Error Correction (QEC) which can totally fix errors but is currently very expensive in terms of number of components needed. Also, SEEQA will explore and advance some of the more recent and sophisticated ideas for handling measurement errors -- if you can't trust the output of the quantum computer you are very limited! 3. Finally, SEEQA will focus on the interrelationship between the architecture or protocol we would like to perform, and the available hardware architecture (including noise sources and other imperfections, the 'topology' which means the question of which qubits can directly 'see' other qubits, and so on). Although quite a bit is known about this, there remain a great many questions within the two themes (a) "what algorithms can run well on my architecture?", and (b) "what architectures can my algorithm run on?"Underpinning all this theoretical research, it will be vital to be able to test things out. The SEEQA project will have two kinds of provision: First, very efficient software that runs on conventional computers to 'pretend' to be quantum computers - exactly simulating them using the well-known laws of quantum physics. However it will only ever be possible to work with small emulated quantum computers because the quantum state is so complex. So it is vital that SEEQA also has access to real prototype quantum processors -- and as many as possible because they are various types. Fortunately SEEQA has multiple letters of support, offering resources approaching £500k, from pioneering UK hardware companies that have working quantum prototypes right now. They will make available their experts and their devices to SEEQA in order to help us to succeed.