Juraschek Dominik M, Meier Quintin N, Narang Prineha
Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, USA.
Department of Materials, ETH Zurich, CH-8093 Zürich, Switzerland.
Phys Rev Lett. 2020 Mar 20;124(11):117401. doi: 10.1103/PhysRevLett.124.117401.
It has recently been indicated that the hexagonal manganites exhibit Higgs- and Goldstone-like phonon modes that modulate the amplitude and phase of their primary order parameter. Here, we describe a mechanism by which a silent Goldstone-like phonon mode can be coherently excited, which is based on nonlinear coupling to an infrared-active Higgs-like phonon mode. Using a combination of first-principles calculations and phenomenological modeling, we describe the coupled Higgs-Goldstone dynamics in response to the excitation with a terahertz pulse. Besides theoretically demonstrating coherent control of crystallographic Higgs and Goldstone excitations, we show that the previously inaccessible silent phonon modes can be excited coherently with this mechanism.
最近有研究表明，六角锰酸盐呈现出类似希格斯和戈德斯通的声子模式，这些模式会调制其主要序参量的幅度和相位。在此，我们描述了一种机制，通过该机制可以相干激发一种类似戈德斯通的无声声子模式，该机制基于与红外活性的类似希格斯声子模式的非线性耦合。结合第一性原理计算和唯象模型，我们描述了太赫兹脉冲激发下耦合的希格斯 - 戈德斯通动力学。除了从理论上证明对晶体学希格斯和戈德斯通激发的相干控制外，我们还表明，利用这种机制可以相干激发以前无法触及的无声声子模式。
