arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1707.01657cond-mat.mes-hall
收藏

拓扑绝缘体Bi2Se3在体耗尽区场效应晶体管的射频量子电容

RF-quantum capacitance of the topological insulator Bi2Se3 in the bulk depleted regime for field-effect transistors

A. Inhofer, J. Duffy, M. Boukhicha, E. Bocquillon, J. Palomo, K. Watanabe, T. Taniguchi, I. Estève, J. M. Berroir, G. Fève, B. Plaçais, B. A. Assaf

摘要:

在射频范围内实现了一种基于hBN封装CVD生长Bi 2Se 3的金属-介质-拓扑绝缘体电容器器件。提取的RF量子电容和器件电阻的频率高达10 GHz,并研究作为施加的栅极电压的函数。高质量的hBN电介质栅极与CVD生长的Bi 2Se 3(在8 nm中n~10^18cm-3)的优化的输运特性的组合允许我们通过电介质栅极获得体耗尽状态。观察到的量子电容最小值揭示了一个纯粹的狄拉克制度,其中狄拉克表面状态接近栅极达到电荷中性,但底表面狄拉克锥保持带电,并通过绝缘体耦合电容到顶表面。我们的工作为在射频器件中实现拓扑材料铺平了道路。

英文摘要:

A Metal-dielectric-topological insulator capacitor device based on hBN-encapsulated CVD grown Bi2Se3 is realized and investigated in the radio frequency regime. The RF quantum capacitance and device resistance are extracted for frequencies as a high as 10 GHz, and studied as a function of the applied gate voltage. The combination of the superior quality hBN dielectric gate with the optimized transport characteristics of CVD grown Bi2Se3 (n~10^18cm-3 in 8 nm) allow us to attain a bulk depleted regime by dielectric gating. A quantum capacitance minimum is observed revealing a purely Dirac regime, where the Dirac surface state in proximity to the gate reaches charge neutrality, but the bottom surface Dirac cone remains charged, and couples capacitively to the top surface via the insulating bulk. Our work paves the way towards implementation of topological materials in RF devices.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑