微潘寧阱陣列離子阱系統的冷卻和位元閘設計

Abstract

離子阱系統由於其相當長的相關時間以及同種的離子的一致性，在量子計算領域中展現了其高度的可行性和可靠性。然而糾纏大量的離子量子位元依然是個重大的挑戰。近幾年來，提出了一種被稱為微潘寧阱陣列的方案，有望突破傳統方法的限制。在這篇論文中，我們首先展示微潘寧阱陣列的基本機制，並接著著重於其在基態冷卻和實現兩量子位元閘的獨特特性。在基態冷卻部分，我們發現微潘寧阱陣列提供了獨特的優勢。即便系統從蘭姆-迪克區域外開始冷卻，也能在不遇到居量束縛的情況下實現基態冷卻。我們還利用微潘寧阱陣列能個別離子的調控軸向頻率的能力，以簡化與兩量子位元閘有關的運動並使保真度不增加超過10−2。因此，兩量子位元閘的複雜性和雷射功率需求可以被大大降低。我們的發現表明，微潘寧阱陣列在量子計算上展現了相當的潛力。

Trapped ion system represents a highly promising and viable platform for quantum computing due to their long coherence time and the uniformity exhibited by ions of the same species. However, entangling a large number of ion qubits remains a significant challenge in this domain. In recent years, a novel approach called the micro-Penning trap array has been proposed as a potential solution to overcoming some of the limitations encountered in conventional schemes. In this thesis, we first demonstrate the fundamental mechanics of the micro-Penning trap array. We then focus on its unique properties in the domain of ground-state cooling and the implementation of two-qubit gates. Regarding ground state cooling, we discover that the micro-Penning trap array offers a distinct advantage of enabling ground-state cooling without encountering population trapping issues, even when the system initiates cooling outside the Lamb-Dicke regime. Additionally, we utilize the capability of individually modulating axial frequency for each ion within the micro-Penning trap array to simplify the associated motion in two-qubit gates without increasing infidelity more than 10−2. As a result, the complexity and laser power requirements of the two-qubit gate pulse can be significantly reduced. Our discoveries suggest that the micro-Penning trap system exhibits great potential for quantum computing.