近日，美国哈佛大学的Marko Loncar&Kazuhiro Kuruma及其研究团队取得一项新进展。经过不懈努力，他们利用声子晶体控制高频声子与单量子系统之间的相互作用。相关研究成果已于2024年12月18日在国际知名学术期刊《自然—物理学》上发表。
本研究展示了利用声子晶体控制宿主基质中声子局域态密度的能力，并测量了这一方法对单个量子系统的积极影响。研究人员设计并制造了特征尺寸小至约20纳米的金刚石声子晶体，从而在50至70吉赫兹的高频段内实现了完全的声子带隙。
通过嵌入在声子晶体中的单个硅空穴色心，研究人员对工程化后的局域态密度进行了探测。观察到与体材料相比，发射体的声子诱导轨道弛豫速率降低了18倍，从而证明了声子晶体能够抑制自发单声子过程。
此外，研究人员还表明，该研究方法可以有效地抑制高达20开尔文温度下的单声子-发射体相互作用，这为研究发射体中的多声子过程提供了可能。本研究结果为实现可用于量子声学动力学和量子声子网络的高效声子-发射体界面迈出了重要一步。
据悉，在量子科学领域，从量子信息处理到传感技术等多个方面，控制固体中的声子至关重要。当固态量子系统与宿主基质中的声子浴相互作用时，声子往往会成为噪声和退相干的来源。
附：英文原文
Title: Controlling interactions between high-frequency phonons and single quantum systems using phononic crystals
Author: Kuruma, Kazuhiro, Pingault, Benjamin, Chia, Cleaven, Haas, Michael, Joe, Graham D., Assumpcao, Daniel Rimoli, Ding, Sophie Weiyi, Jin, Chang, Xin, C. J., Yeh, Matthew, Sinclair, Neil, Loncar, Marko
Issue&Volume: 2024-12-18
Abstract: The ability to control phonons in solids is key in many fields of quantum science, ranging from quantum information processing to sensing. Phonons often act as a source of noise and decoherence when solid-state quantum systems interact with the phonon bath of their host matrix. In this study, we demonstrate the ability to control the phononic local density of states of the host matrix using phononic crystals and measure its positive impact on single quantum systems. We design and fabricate diamond phononic crystals with features down to around 20nm, resulting in a high-frequency complete phononic bandgap from 50 to 70GHz. The engineered local density of states is probed using single silicon-vacancy colour centres embedded in the phononic crystals. We observe an 18-fold reduction in the phonon-induced orbital relaxation rate of the emitters compared to bulk, thereby demonstrating that the phononic crystal suppresses spontaneous single-phonon processes. Furthermore, we show that our approach can efficiently suppress single-phonon–emitter interactions up to 20K, allowing the investigation of multi-phonon processes in the emitters. Our results represent an important step towards the realization of efficient phonon–emitter interfaces that can be used for quantum acoustodynamics and quantum phononic networks.
DOI: 10.1038/s41567-024-02697-5
Source: https://www.nature.com/articles/s41567-024-02697-5