Robust high-fidelity entangling gates using long-wavelength radiation for quantum computation

量子计算是一个发展中的领域，有望解决经典计算机难以解决的问题。然而，只有在使用容错量子计算机的情况下，才能找到这些问题的解决方案。这种设备所需要的资源是能够可靠地存储信息的大量量子比特和执行计算的高保真量子门，此外，为了能够可靠地执行运算，必须实施纠错协议。实验证明，这可以在噪声有限的情况下实现，这对门保真度的下限施加了限制，误差阈值范围在10-4到10-2之间，具体取决于所使用的噪声模型。纠错协议使用多个物理量子比特来编码一个逻辑量子比特，该逻辑量子比特将用作计算中使用的单位。因此，在计算所需的物理量子比特的数量和门的保真度之间存在权衡：保真度越高，补偿门误差所需的额外量子比特的数量就越少。考虑和克服这些挑战将使量子算法的实施成为可能。拟议的项目将研究可用于实现纠缠门的技术，并提高它们的保真度、速度和整体稳健性。这将需要减少噪声源对门功能的影响，这可能导致对硬件设置的设计修改。一旦完成了这些改进，该项目将专注于演示量子算法。与实验工作同时完成的一个平行项目是进行的实验的自动化。这将使过去的硬件能够远程访问，并成为使该系统可用于解决不同问题的垫脚石。

Quantum computing is a developing field that promises to solve problems which are too hard for a classical computer. However, solutions for these problems can only be found if a fault-tolerant quantum computer is used. The resources needed for such a device are a large number of qubits that can reliably store information and high-fidelity quantum gates to execute the computation.Furthermore, to be able to reliably perform operations, error correction protocols should be implemented. It was proven that this can be achieved in the presence of limited noise, which imposes a constraint on the lower limit for the gate fidelities, the error thresholds range between 10-4 and 10-2, depending on the noise model used. Error correction protocols use multiple physical qubits to encode a logical qubit, which will be used as the unit employed in computation. Consequently, there is a trade-off between the number of physical qubits necessary for computation and the gate fidelity: the higher the fidelity, the smaller the number of additional qubits needed to compensate for the gate-errors. Considering and overcoming these challenges will enable the implementation of quantum algorithms. The proposed project will research techniques that can be used to implement entangling gates and increase their fidelity, speed and overall robustness. This will require to reduce the effect of noise sources on the gate functionality, which can lead to designing modifications to the hardware setup. Once these improvements have been made, the project will focus on demonstrating quantum algorithms. A parallel project that will be completed alongside the experimental work is the automation of the conducted experiments. This will enable the hardware used to be remotely accessible and it is a stepping stone towards making the system available to be used in solving different problems.