The discovery of atom-like spin emitters associated with defects in two-dimensional (2D) wide-bandgap (WBG) semiconductors presents new opportunities for highly tunable and versatile qubits. So far, the study of such spin emitters has focused on defects in hexagonal boron nitride (hBN). However, hBN necessarily contains a high density of nuclear spins, which are expected to create a strong incoherent spin-bath that leads to poor coherence properties of spins hosted in the material. Therefore, identification of new qubit candidates in other 2DWBG materials is necessary. Given the time demands of ab initio methods, new approaches for rapid screening and calculations of identifying properties of suitable atom-like qubits are required. In this work, we present two new methods for rapid estimation of the zero-phonon line (ZPL), a key property of atomic qubits in WBG materials. First, the ZPL is calculated by exploiting Janak’s theorem. For finite changes in occupation, we provide the leading-order estimate of the correction to the ZPL obtained using Janak’s theorem, which is more rapid than the standard method ($\mathrm{\Delta }$SCF). Next, we demonstrate an approach to converging excited states that is faster for systems with small strain than the standard approach used in the $\mathrm{\Delta }$SCF method. We illustrate these methods using the case of the singly negatively charged calcium vacancy in SiS${}_2$, which we are the first to propose as a qubit candidate. This work has the potential to assist in accelerating the high-throughput search for quantum defects in materials, with applications in quantum sensing and quantum computing.

中文翻译：

---

加速范德华材料中原子量子位候选物的高通量筛选的方法

与二维 (2D) 宽带隙 (WBG) 半导体中的缺陷相关的类原子自旋发射体的发现为高度可调和通用的量子位提供了新的机会。到目前为止，对这种自旋发射器的研究主要集中在六方氮化硼 (hBN) 中的缺陷。然而，hBN 必然包含高密度的核自旋，预计会产生强烈的非相干自旋浴，导致材料中自旋的相干性较差。因此，有必要在其他 2DWBG 材料中识别新的量子位候选者。鉴于从头开始的时间要求方法，需要新的方法来快速筛选和计算识别合适的类原子量子位的特性。在这项工作中，我们提出了两种快速估计零声子线 (ZPL) 的新方法，这是 WBG 材料中原子量子位的关键特性。首先，ZPL 是通过利用 Janak 定理来计算的。对于占用的有限变化，我们提供了对使用 Janak 定理获得的 ZPL 的修正的领先阶估计，这比标准方法更快（$\mathrm{\Delta }$SCF）。接下来，我们展示了一种收敛激发态的方法，对于小应变系统来说，这种方法比实验中使用的标准方法更快。$\mathrm{\Delta }$SCF 方法。我们使用 SiS 中带负电荷的钙空位的情况来说明这些方法${}_2$，我们是第一个提出作为量子位候选者的人。这项工作有可能有助于加速材料中量子缺陷的高通量搜索，并应用于量子传感和量子计算。