Advancing the practical implementation of quantum error correction with fault-tolerant syndrome extraction

量子计算机是一种新型的功能强大的计算机，它基于被称为量子比特或量子位的构建块，比传统计算机上的比特更有效地携带信息。然而，比特和量子位都可能受到错误的影响，这些错误会改变它们所包含的信息。为了使量子计算机能够准确地执行复杂的计算并具有商业价值，我们需要能够“纠正”这些错误。这是量子计算的最大瓶颈。一旦解决，它将成为量子工业的转折点，将量子计算机变成极其强大的机器。但事情并没有那么简单。根据量子力学，每当我们试图“读取”一个量子比特时，信息就会被破坏。因此，我们需要使用第二组量子比特来告诉我们是否以及在哪里发生了错误，而不会干扰携带原始信息的量子比特。然而，收集这种间接信息——一种称为综合征提取的过程——也可能引入错误。我们将通过开发代码以尽可能准确的方式进行综合征提取来解决这一挑战。然后我们将在一台真正的量子计算机上测试这些代码。在这个项目中，英国领先的量子软件公司Riverlane将与Rigetti密切合作，Rigetti是一家开发基于超导电路的量子计算机的公司。Rigetti拥有英国最强大的量子机器，到2023年初将拥有80个量子比特。我们将共同努力，将量子软件和硬件结合起来，在量子计算机中实现纠错方面迈出一大步。这是量子计算机变得足够强大和稳定以解决需要复杂计算的现实世界问题的唯一途径。我们的项目汇集了英国最好的量子软件和硬件公司，能够完成这项任务。我们的工作将加强英国量子产业，加速量子计算机的生产，这将改变几个行业，如药物发现和材料开发。

Quantum computers are a new type of powerful computer, based on building blocks called quantum bits, or qubits, that carry information in a more effective way than bits on a conventional computer. However, both bits and qubits can be affected by errors that change the information they contain.For quantum computers to perform complex calculations accurately and become commercially useful, we need to be able to 'correct' these errors. This is the biggest bottleneck in quantum computing. When solved, it will be the turning point in the quantum industry, turning quantum computers into extremely powerful machines. But it is not that simple. According to quantum mechanics, every time we try and 'read' a qubit, the information gets destroyed. We therefore need to use a second group of qubits that will tell us if and where an error occurred without disturbing the qubits carrying the original information. However, collecting this indirect information -- a process called syndrome extraction - can introduce errors too.We will solve this challenge by developing codes to perform syndrome extraction in the most accurate way possible. We'll then test these codes on a real quantum computer. In this project, the UK's leading quantum software company, Riverlane, will work closely with Rigetti, a company developing quantum computers based on superconducting circuits. Rigetti owns the most powerful quantum machine in the UK, which will feature 80 qubits in early 2023\. We will work together to combine quantum software and hardware to take a first big step in implementing error correction in quantum computers. This is the only way for quantum computers to become powerful and stable enough to solve real-world problems that require complicated computations. Our project brings together the best UK companies in quantum software and hardware able to deliver on this task. Our work will strengthen the UK quantum industry and accelerate the production of quantum computers that will transform several industries, such as drug discovery and materials development.