标题： 工程退相干：表征与抑制 显示英文标题

标题： Engineered Decoherence: Characterization and Suppression

摘要： 由于无处不在的环境干扰，量子相干性在一定时间尺度上不可避免地经历不可逆的转变，从而导致编码信息的丢失。 这一过程被称为退相干，是实现高效量子信息处理器的主要障碍。 理解退相干的机制对于开发抑制它的工具至关重要。 在这里，我们采用Cory及其同事[Phys. Rev. A 67, 062316 (2003)]提出的方法，通过随机扰动其周围的辅助量子比特来在系统量子比特中设计人工退相干。 使用一个两量子比特核磁共振量子寄存器，我们通过噪声光谱和量子过程层析成像来表征人工退相干。 此外，我们研究了动态解耦序列在抑制人工退相干方面的有效性。 这里我们描述实验结果及其与理论模拟的比较。 显示英文摘要

摘要： Due to omnipresent environmental interferences, quantum coherences inevitably undergo irreversible transformations over certain time-scales, thus leading to the loss of encoded information. This process, known as decoherence, has been a major obstacle in realizing efficient quantum information processors. Understanding the mechanism of decoherence is crucial in developing tools to inhibit it. Here we utilize a method proposed by Cory and co-workers [Phys. Rev. A 67, 062316 (2003)] to engineer artificial decoherence in the system qubits by randomly perturbing their surrounding ancilla qubits. Using a two qubit nuclear magnetic resonance quantum register, we characterize the artificial decoherence by noise spectroscopy and quantum process tomography. Further, we study the efficacy of dynamical decoupling sequences in suppressing the artificial decoherence. Here we describe the experimental results and their comparisons with theoretical simulations.