腔磁振子学与布拉格和反布拉格镜中的连续谱束缚态
Cavity magnonics and bound states in the continuum with Bragg and anti-Bragg mirrors
- City University of Hong Kong（香港城市大学）
- Tianjin University（天津大学）
- Chalmers University of Technology（查尔姆斯理工大学）
- Shanghai Institute of Microsystem and Information Technology, CAS（中国科学院上海微系统与信息技术研究所）
机构由 AI 辅助整理，请以论文原文为准。
AI总结：
本文实验演示了腔磁振子学中布拉格和反布拉格镜的连续谱束缚态，实现了暗超模与探测磁振子的相干耦合，并通过扫描探针进行位置依赖探测，为探测奇异态和非厄米物理提供了新平台。
AI中文摘要：
周期性的谐振发射体阵列耦合到一维波导时可以充当镜子。一个典型的例子是布拉格镜，其中发射体按半波长的整数倍间隔排列，并集体增强光的反射。两个这样的镜子构成一个有效腔，该腔能够容纳连续谱中的束缚态（BICs）。然而，生成和探测此类BICs的空间分布已被证明具有挑战性。在这里，我们通过使用两个周期性的铁磁球阵列和一个探测球，在双开放波导架构中实验演示了腔磁振子学中的BICs。我们实现了布拉格腔和反布拉格腔，它们的镜子具有不同的晶格常数。在布拉格腔中，存在由镜子球形成的简并超模。我们展示了一个单一的暗超模与腔区域中的探测磁振子相干耦合，形成两个极化子，其分裂幅度与探测球尺寸和镜子球数量均成比例。相比之下，反布拉格腔在带隙中具有亮超模和暗超模，显著改变了磁振子-腔相互作用。此外，通过移动探测球，我们对腔场进行了位置依赖的探测，突出了BICs在这些腔中的作用。我们灵活的实验装置配备扫描探针，为探测由光-物质相互作用产生的其他奇异态、与混合量子网络中的超导电路接口以及研究布拉格和反布拉格腔的非厄米物理提供了可能性。
英文摘要：
A periodic resonant emitter array coupled to a one-dimensional waveguide can act as a mirror. A typical example is a Bragg mirror, where emitters are spaced by multiples of half wavelengths and collectively enhance light reflection. Two such mirrors form an effective cavity that hosts bound states in the continuum (BICs). However, generating and detecting the spatial profiles of such BICs has proven challenging. Here, we experimentally demonstrate BICs in cavity magnonics using two periodic ferrimagnetic-sphere arrays and a probe sphere in a dual-open-waveguide architecture. We realize both Bragg and anti-Bragg cavities, whose mirrors have different lattice constants. In the Bragg cavity, there are degenerate supermodes formed by mirror spheres. We show that a single dark supermode coherently couples to the probe magnon in the cavity region, forming two polaritons whose splitting scales with both the probe-sphere size and the number of mirror spheres. By contrast, the anti-Bragg cavity has bright and dark supermodes in a bandgap, substantially changing the magnon-cavity interaction. Moreover, by moving the probe sphere, we perform position-dependent detection of the cavity field, highlighting the role of BICs in these cavities. Our flexible experimental setup with a scanning probe opens possibilities to detect other exotic states created by light-matter interaction, to interface with superconducting circuits in hybrid quantum networks, and to study non-Hermitian physics with Bragg and anti-Bragg cavities.
