Large nonsaturating magnetoresistance and pressure-induced phase transition in the layered semimetal HfTe 2
Large nonsaturating magnetoresistance and pressure-induced phase transition in the layered semimetal HfTe 2
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DOI：
10.1103/physrevb.96.205148
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发表时间：
2017-11
影响因子：
3.7
通讯作者：
S. Mangelsen;P. Naumov;O. Barkalov;S. Medvedev;W. Schnelle;M. Bobnar;S. Mankovsky;S. Polesya;Christian Näther;Hubert Ebert;Wolfgang Bensch
中科院分区：
文献类型：
--
作者：
S. Mangelsen;P. Naumov;O. Barkalov;S. Medvedev;W. Schnelle;M. Bobnar;S. Mankovsky;S. Polesya;Christian Näther;Hubert Ebert;Wolfgang Bensch
具有Dirac点或Weyl点的半金属中出现的大磁阻(MR)和超导电性等不寻常的物理性质通常与它们的拓扑非平凡能带结构有关。然而，有越来越多的关于半金属的报告显示，在没有狄拉克或韦尔点的情况下，MR很大。本文报道了层状过渡金属二卤化物的实验和理论研究，在没有狄拉克或魏尔点的情况下，在$T=2$K处有较大的MR为1350%，${\ensuremath{\mu}}_{0}H=9\phantom{\rule{0.16em}{0ex}}\mathrm{T}$。此外，压力下的结构和电阻率显示出独特的结构转变。这些结果清楚地区分了TMDCs和TMDCs，它们都表现出较大的MR，并被视为Weyl半金属。对于进一步研究特定能带结构特征的相互作用及其与新出现的物理性质的关系，$\mathm{hft}{\mathm{e}}_{2}$是一个很有吸引力的平台。
Unusual physical properties like large magnetoresistance (MR) and superconductivity occurring in semimetals with Dirac or Weyl points are often linked to their topologically nontrivial band structures. However, there is an increasing number of reports on semimetals that show large MR in the absence of Dirac or Weyl points. Herein we report an experimental and theoretical study on the layered transition-metal dichalcogenide (TMDC) $\mathrm{HfT}{\mathrm{e}}_{2}$ that shows a large MR of $1350%$ at $T=2$ K and ${\ensuremath{\mu}}_{0}H=9\phantom{\rule{0.16em}{0ex}}\mathrm{T}$ in the absence of Dirac or Weyl points. Moreover, the structure and electrical resistivity under pressure reveal a unique structural transition. These results clearly distinguish $\mathrm{HfT}{\mathrm{e}}_{2}$ from TMDCs like $\mathrm{MoT}{\mathrm{e}}_{2}$ or $\mathrm{WT}{\mathrm{e}}_{2}$ which both exhibit larger MR and are viewed as Weyl semimetals. $\mathrm{HfT}{\mathrm{e}}_{2}$ is an appealing platform for future investigations on the interplay of particular band-structure features and their connection to emerging physical properties.