声子晶体中的声谷态输运

如同自旋电子学中的自旋，固体中的能谷自由度可视为新的信息载体，从而用于未来的电子器件设计。最近，作者将谷态的概念引入到声子晶体中，揭示其涡旋属性并建立激发选择定则。有趣的是，声谷态可由外部声场直接激发，并通过探测声子晶体内外的声场分布展示其极化特性。这种涡旋手性锁定的谷输运将为人们提供全新的声波操控方式。考虑到声和物质的相互作用，也可预期谷涡旋态的其它新奇应用，如旋转操纵微颗粒等。进一步研究发现，存在两类拓扑非平庸的声谷霍尔相，它们之间的界面可以支持拓扑保护的边缘态。研究表明，该边缘态具备各种新颖的性质，如谷选择性激发、边界拐弯抗反射等。

Valley transport in sonic crystals

Like the spin in spintronics, the valley index in solid-state materials can be viewed as a new carrier of information, which is useful for designing modern electronic devices. Recently, we have applied the concept of valleytronics to sonic crystals, revealed the vortex nature of valley states, and established valley-selection rules. Interestingly, the acoustic valley states can be stimulated directly by external sound, and detected through the field distributions inside and outside the crystal. The vortex chirality-locked valley transport enables a novel manipulation of sound. Considering the interaction between sound and matter, other fancy applications can also be anticipated for the valley vortex states, such as rotating micro-particles. In addition, we find that there exist two kinds of topologically distinct acoustic valley Hall phases, and an interface separating them can host topologically-protected edge states, associated with many exotic transport properties (such as valley selective excitations and antireflection in bent corners).