Samarakoon Anjana, Sato Taku J, Chen Tianran, Chern Gai-Wei, Yang Junjie, Klich Israel, Sinclair Ryan, Zhou Haidong, Lee Seung-Hun
Department of Physics, University of Virginia, Charlottesville, VA 22904.
Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Katahira, Sendai 980-8577, Japan.
Proc Natl Acad Sci U S A. 2016 Oct 18;113(42):11806-11810. doi: 10.1073/pnas.1608057113. Epub 2016 Oct 3.
The notion of complex energy landscape underpins the intriguing dynamical behaviors in many complex systems ranging from polymers, to brain activity, to social networks and glass transitions. The spin glass state found in dilute magnetic alloys has been an exceptionally convenient laboratory frame for studying complex dynamics resulting from a hierarchical energy landscape with rugged funnels. Here, we show, by a bulk susceptibility and Monte Carlo simulation study, that densely populated frustrated magnets in a spin jam state exhibit much weaker memory effects than spin glasses, and the characteristic properties can be reproduced by a nonhierarchical landscape with a wide and nearly flat but rough bottom. Our results illustrate that the memory effects can be used to probe different slow dynamics of glassy materials, hence opening a window to explore their distinct energy landscapes.
复杂能量景观的概念支撑着许多复杂系统中有趣的动力学行为，这些系统涵盖从聚合物、大脑活动到社会网络以及玻璃态转变等领域。在稀磁合金中发现的自旋玻璃态，一直是研究由具有崎岖漏斗状的分层能量景观所导致的复杂动力学的极为便利的实验框架。在此，我们通过体磁化率和蒙特卡罗模拟研究表明，处于自旋阻塞状态的密集受挫磁体所表现出的记忆效应比自旋玻璃弱得多，并且其特征性质可以由具有宽阔且近乎平坦但粗糙底部的非分层景观来重现。我们的结果表明，记忆效应可用于探测玻璃态材料不同的慢动力学，从而为探索它们独特的能量景观打开了一扇窗口。
