大D反铁磁体DTN中的压力调节量子关键性
Kirill Yu Povarov1, David E Graf2, Andreas Hauspurg3,4
1Dresden High Magnetic Field Laboratory (HLD-EMFL) and Würzburg-Dresden Cluster of Excellence ct.qmat, Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Dresden, Germany. k.povarov@hzdr.de.
我们发现,对量子反铁磁体DTN施加压力会导致磁性相位过渡. 这一发现使得DTN成为研究量子关键现象的理想系统,其动态指数为z=1.1.
科学领域:
- 凝聚物质物理学 凝聚物质物理学
- 量子磁力 量子磁力 量子磁力
- 材料科学 材料科学 材料科学
背景情况:
- 强烈相关的自旋系统表现出由外部参数驱动的量子临界点.
- 间隙量子反铁磁体可以在压力或磁场下过渡到磁性有序状态.
- 动态临界指数 (z=1或z=2) 根据旋转激发分散来表征这些过渡.
研究的目的:
- 为了研究量子反铁磁体NiCl2⋅4SC(NH2) 2 (DTN) 中的压力诱导相变.
- 要确定与此过渡相关的动态临界指数.
- 建立DTN作为研究量子关键性的模型系统.
主要方法:
- 在不同压力下进行高频感应和超声波测量.
- 高压电子自旋共振 (ESR) 光谱学.
- 粉末中子衍射分析格子结构和对称性.
- 密度矩阵重规范化组 (DMRG) 的计算.
主要成果:
- 在DTN中,由于旋转间隙的关闭,压力诱导的磁性订单转换在大约4.2 kbar.
- 在过渡压力下保持高旋转对称性和没有格子扭曲.
- 对z=1动态临界指数场景的实验证实.
- 实验数据与DMRG对关键参数的计算之间的定量一致性.
结论:
- DTN 作为探索 z=1 量子关键现象的典范材料.
- 在DTN的压力驱动过渡提供了一个干净的平台来研究量子关键性的基本方面.
- 这项研究量化地将理论模型与可调量的量子磁铁中的实验观测联系起来.
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