As it has been demonstrated that trapped ion systems have unmatched long-lived quantum-bit (qubit) coherence and can support high-fidelity quantum manipulations, how to scale up the system size becomes an inevitable task for practical purposes. In this work, we theoretically analyse the physical limitation of scalability with a trapped ion array, and propose a feasible scheme of architecture that in principle allows an arbitrary number of ion qubits, for which the overhead only scales linearly with the system size. This scheme relies on the combined ideas of a trap architecture of tunable size, stabilisation of an ion crystal by optical tweezers, and continuous sympathetic cooling without touching the stored information. We demonstrate that illumination of optical tweezers modifies the motional spectrum by effectively pinning the ions, lifting the frequencies of the motional ground modes. By doing so, we make the structure of the array less vulnerable from thermal excitations, and suppress the the position fluctuations to insure faithful gate operations. Finally, we also explore the local behaviour of cooling when a sub-array is isolated by optical tweezers from other parts of the crystal.

中文翻译：

---

通过离子晶体上的光镊稳定的可扩展量子计算

由于已证明俘获离子系统具有无与伦比的长寿命量子位 (qubit) 相干性，并且可以支持高保真量子操作，因此如何扩大系统规模成为实际应用中不可避免的任务。在这项工作中，我们从理论上分析了俘获离子阵列可扩展性的物理限制，并提出了一种可行的架构方案，原则上允许任意数量的离子量子位，其开销仅与系统大小成线性比例。该方案依赖于尺寸可调的陷阱结构、光镊稳定离子晶体以及不接触存储信息的连续交感冷却的组合思想。我们证明光镊的照明通过有效地固定离子来修改运动光谱，提升运动地面模式的频率。通过这样做，我们使阵列结构不易受到热激发的影响，并抑制位置波动以确保可靠的门操作。最后，我们还探索了当子阵列通过光镊与晶体的其他部分隔离时的局部冷却行为。