Taming the Noisy Environment for Photon-Mediated Operations in Quantum Information Processing

量子信息处理（QIP）平台的基本构建块是量子位或量子位，它可以被认为是具有两个能级的量子系统。这些能级之间的跃迁伴随着光子（光粒子）的发射/吸收，其能量/频率对应于跃迁。对于许多系统，量子比特的波动环境会引起光谱扩散，即发射/吸收光子频率随时间的随机漂移。这种现象限制了不同量子比特之间的光子介导操作的效率，而这些操作对于实现大规模量子平台至关重要。该项目的目标是开发基于外部施加的控制场的协议，以使这些光子介导的操作对量子比特环境中的波动具有弹性，从而提高这些操作的效率，以构建大规模QIP平台。已成功实现为量子比特的不同系统都表现出特定的有利物理特性。因此，对于未来向大规模QIP平台的发展，以互补的方式使用不同类型的量子位，使得每个系统都可以用于其最适合的应用，这是一条可行的途径。在这种情况下，静止到飞行的量子比特转换和其他光子介导的操作是必不可少的，成功的实现取决于它们的效率。该项目的目标是研究量子发射体在扩散诱导浴中的动力学，以便它们的光学特性可以根据特定的QIP要求进行定制，尽管它们的环境会产生有害影响。PI将使用分析和计算方法的组合来评估不同量子发射器的特性及其在适当的脉冲和连续波协议驱动下在各种QIP操作中的性能。PI将考虑对光谱扩散敏感的量子发射器的不同配置，包括两级、三级和多级系统，以及在相关QIP操作中耦合到辐射浴的量子发射器的集合。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

The fundamental building block of Quantum Information Processing (QIP) platforms is the quantum bit or qubit, which can be thought of as a quantum system with two energy levels. Transitions between these levels are accompanied by the emission/absorption of a photon, a particle of light, with the energy/frequency corresponding to the transition. For many systems, the fluctuating environment of the qubit induces spectral diffusion, a random drift in time of the emitted/absorbed photon frequency. This phenomenon limits the efficiency of photon-mediated operations between different quantum bits, and these operations are essential for the realization of large scale quantum platforms. The goal of this project is to develop protocols that will be based on externally applied control fields for the purpose of making these photon-mediated operations resilient to fluctuations in the qubit environment and thus improve the efficiency of these operations for the construction of large scale QIP platforms.The different systems that have been successfully implemented as quantum bits each exhibit specific advantageous physical properties. Thus, for future advances towards large scale QIP platforms, using different types of qubit in a complementary manner, so that each system can be exploited for its best suited application, is a viable avenue. In this context, stationary-to-flying qubit conversion and other photon-mediated operations are essential and successful implementations depend on their efficiency. The goal of this project is to study the dynamics of quantum emitters in diffusion-inducing baths so that their optical properties can be tailored to specific QIP requirements despite deleterious effects of their environment. The PI will use a combination of analytical and computational approaches to evaluate properties of different quantum emitters and their performance in various QIP operations when they are driven by appropriate pulse and continuous wave protocols. The PI will consider different configurations of quantum emitters susceptible to spectral diffusion including two-level, three level and many-level systems and ensembles of such quantum emitters coupled to radiation baths in relevant QIP operations.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.