Berry Curvature-Driven Valley Nernst Effect in Monolayer WSe2

IF 9.6 1区材料科学 Q1 CHEMISTRY, MULTIDISCIPLINARY

Nano Letters Pub Date : 2025-04-09 DOI:10.1021/acs.nanolett.5c00194

Jae Won Choi, Won-Yong Lee, Takashi Kikkawa, Min-Sung Kang, Gil-Sung Kim, Jung-Min Cho, No-Won Park, Yun-Ho Kim, Young-Gui Yoon, Chinh Tam Le, Yong Soo Kim, Eiji Saitoh, Sang-Kwon Lee

引用次数: 0

Abstract

The Berry curvature in a Dirac cone causes anomalous transport phenomena, including anomalous Hall, anomalous Nernst, and Valley Hall effects. Detecting the Berry curvature in a 2D transition metal dichalcogenide (TMD) layer requires breaking time-reversal symmetry to create a population imbalance between the K⁺ and K^– valleys. Direct observation and control of valley polarization in a 2D TMD layer remain challenging, especially for practical applications. Here, we present the first experimental verification of the Berry curvature-driven valley Nernst effect (VNE) in interlayer TMDs, focusing on the monolayer (ML) WSe₂ in a Pt/YIG bilayer structure. Experiments and calculations show that our VNE signals result from the high Berry curvature of the ML WSe₂ layer. This opens up a new way to generate spin- and valley-current-based thermoelectric devices.

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狄拉克锥中的贝里曲率会导致反常输运现象，包括反常霍尔效应、反常奈恩斯特效应和谷霍尔效应。在二维过渡金属二钙化物（TMD）层中检测贝里曲率需要打破时间反向对称性，在 K+ 和 K- 谷之间产生种群失衡。直接观察和控制二维 TMD 层中的谷极化仍具有挑战性，尤其是在实际应用中。在此，我们首次通过实验验证了层间 TMD 中贝里曲率驱动的谷内效应 (VNE)，重点研究了 Pt/YIG 双层结构中的单层 (ML) WSe2。实验和计算表明，我们的 VNE 信号来自 ML WSe2 层的高贝里曲率。这为产生基于自旋和谷电流的热电设备开辟了一条新途径。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Nano Letters 工程技术-材料科学：综合

CiteScore

16.80

自引率

2.80%

发文量

1182

审稿时长

1.4 months

期刊介绍： Nano Letters serves as a dynamic platform for promptly disseminating original results in fundamental, applied, and emerging research across all facets of nanoscience and nanotechnology. A pivotal criterion for inclusion within Nano Letters is the convergence of at least two different areas or disciplines, ensuring a rich interdisciplinary scope. The journal is dedicated to fostering exploration in diverse areas, including: - Experimental and theoretical findings on physical, chemical, and biological phenomena at the nanoscale - Synthesis, characterization, and processing of organic, inorganic, polymer, and hybrid nanomaterials through physical, chemical, and biological methodologies - Modeling and simulation of synthetic, assembly, and interaction processes - Realization of integrated nanostructures and nano-engineered devices exhibiting advanced performance - Applications of nanoscale materials in living and environmental systems Nano Letters is committed to advancing and showcasing groundbreaking research that intersects various domains, fostering innovation and collaboration in the ever-evolving field of nanoscience and nanotechnology.