Chen Hao, Wu Weikang, Zhu Jiaojiao, Yang Zhengning, Gong Weikang, Gao Weibo, Yang Shengyuan A, Zhang Lifa
NNU-SULI Thermal Energy Research Center and Center for Quantum Transport and Thermal Energy Science (CQTES), School of Physics and Technology, Nanjing Normal University, Nanjing 210023, China.
Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore.
Nano Lett. 2022 Feb 23;22(4):1688-1693. doi: 10.1021/acs.nanolett.1c04705. Epub 2022 Feb 11.
The diode effect means that carriers can only flow in one direction but not the other. While diode effects for electron charge, spin, or photon have been widely discussed, it remains a question whether a chiral phonon diode can be realized, which utilizes the chiral degree of freedom of lattice vibrations. In this work, we reveal an intrinsic connection between the chiralities of a crystal structure and its phonon excitations, which naturally leads to the chiral phonon diode effect in chiral crystals. At a certain frequency, phonons with a definite chirality can propagate only in one direction but not the opposite. We demonstrate the idea in concrete materials including bulk Te and α-quartz (SiO). Our work discovers the fundamental physics of chirality coupling between different levels of a system, and the predicted effect will provide a new route to control phonon transport and design information devices.
二极管效应意味着载流子只能沿一个方向流动，而不能反向流动。虽然电子电荷、自旋或光子的二极管效应已被广泛讨论，但能否实现利用晶格振动手性自由度的手性声子二极管仍是一个问题。在这项工作中，我们揭示了晶体结构的手性与其声子激发之间的内在联系，这自然导致了手性晶体中的手性声子二极管效应。在特定频率下，具有确定手性的声子只能沿一个方向传播，而不能反向传播。我们在包括块状碲和α-石英（SiO）在内的具体材料中验证了这一想法。我们的工作发现了系统不同层次之间手性耦合的基本物理原理，并且所预测的效应将为控制声子输运和设计信息器件提供一条新途径。
