Enhancement of 2D topological semimetal transport properties by current annealing
Enhancement of 2D topological semimetal transport properties by current annealing
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DOI：
10.1063/5.0102933
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发表时间：
2022-09
影响因子：
4
通讯作者：
A. Fereidouni;M. Doha;K. Pandey;R. Basnet;J. Hu;H. Churchill
中科院分区：
文献类型：
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作者：
A. Fereidouni;M. Doha;K. Pandey;R. Basnet;J. Hu;H. Churchill
二维拓扑半金属的本征量子输运性质的观测具有挑战性，这是由于在制造过程中引入的外部因素抑制了高迁移率。我们证明了电流退火作为一种方法，以大大提高电子输运性能的二维拓扑半金属薄片。在基于两种拓扑半金属ZrSiSe和BaMnSb 2的剥离薄片的器件中，接触电阻和电阻率分别提高了[公式：见正文]和[公式：见正文]。使用这种方法，在ZrSiSe中的载流子迁移率提高了3800倍，从而观察到剥离的ZrSiSe的创纪录的高迁移率。退火ZrSiSe量子振荡出现在低至5 T的磁场，和磁阻增加了104倍。我们认为，这种改进的基础是热过程。最后，拉曼光谱和量子振荡的分析表明，在ZrSiSe的声子模式和费米表面积不变的电流退火。
Observation of intrinsic quantum transport properties of two-dimensional (2D) topological semimetals can be challenging due to suppression of high mobility caused by extrinsic factors introduced during fabrication. We demonstrate current annealing as a method to substantially improve electronic transport properties of 2D topological semimetal flakes. Contact resistance and resistivity were improved by factors up to [Formula: see text] and [Formula: see text], respectively, in devices based on exfoliated flakes of two topological semimetals, ZrSiSe and BaMnSb2. Using this method, carrier mobility in ZrSiSe was improved by a factor of 3800, resulting in observation of record-high mobility for exfoliated ZrSiSe. Quantum oscillations in annealed ZrSiSe appeared at magnetic fields as low as 5 T, and magnetoresistance increased by a factor of 104. We argue that a thermal process underlies this improvement. Finally, Raman spectroscopy and analysis of quantum oscillations in ZrSiSe indicate that the phonon modes and Fermi surface area are unchanged by current annealing.