Development of Chiral Charge Density Wave Devices

手性电荷密度波器件的研制

• 批准号: 1711015
• 负责人: Goran Karapetrov
• 金额: $ 37万
• 依托单位: Drexel University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-08-01 至 2022-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1711015&HistoricalAwards=false
• 关键词: Development; Chiral; Charge; Density; Wave

The goal of this proposal is to extend our fundamental understanding of the properties of chiral charge density wave materials and utilize its properties in new opto-electronic devices. Manipulation of chiral charge domains will be transformative to the condensed matter physics and it will open the doors to devices based on collective electron excitations. The main advantage of using collective charge systems for electronics is lower power dissipation, high density of information storage and high speed. The fundamental studies will involve both macroscopic electronic and optical properties characterization and atomic scale investigations of the chiral charge density wave properties in carefully engineered two-dimensional materials and devices.The program will provide students and young researchers with necessary tools to carry out modern fundamental research in the fields of materials science, condensed matter physics and optoelectronic device engineering. Since the designed research activities are highly interdisciplinary, the students will be stimulated to take classes across disciplines, such as nanoscience, electron and scanning probe microscopy and nanofabrication. The plan is to broaden participation and appreciation of students through (a) incorporating elements of the research in existing nanoscience, nano-electronics and solid-state physics courses at both the undergraduate and graduate level; (b) train students to use state of the art fabrication and characterization tools and (c) expose the students to research enterprise and collaborative research across different organizations.This work should lead to training a PhD student and several undergraduate students. Outreach to local area high schools through senior thesis work experience and science research clubs as well as College' s open houses are part of the overreaching strategy to prepare high school students to pursue science and engineering degrees.Chirality breaks down the spatial inversion symmetry and results in unexpected new electronic properties, in particular in systems with reduced dimensionality. In many cases the electronic chirality is facilitated by the specific structure of the system in which it emerges, either on atomic scale or on mesoscopic scale. Recently, it was discovered that one of the well-studied macroscopically correlated electronic state, the charge density wave, also exhibits chiral properties. This proposal explores the opportunity to use the nanometer-size domains of opposite chirality that are separated with domain walls as basic elements for memory and logic units.In this proposal we will expand the fundamental understanding of the dynamic nature of the coupling of the chiral CDW with femtosecond optical perturbations and nanosecond current pulses. The dynamics of the excited metastable states through which the system traverses before coming back to equilibrium could include unconventional order such as ferroelectricity, CDW or superconductivity. The origin of these phenomena is in the existence of various types of symmetry breaking (inversion symmetry in TiSe2) that gives rise to degenerate ground states. The opportunity exists to exploit these metastable states in low power electronic devices. We will also optimize the growth of TiSe2 thin films in order to enable efficient device fabrication. The effect on strain and doping on chiral CDW thermodynamics will be explored.

本研究的目的是扩展我们对手性电荷密度波材料性质的基本理解，并将其性质应用于新的光电器件。手征电荷域的操纵将是凝聚态物理学的变革，它将为基于集体电子激发的设备打开大门。电子学中使用集体充电系统的主要优点是功耗低、信息存储密度高和速度快。基础研究将涉及宏观电子和光学性质表征以及精心设计的二维材料和器件中手性电荷密度波性质的原子尺度研究。该计划将为学生和年轻研究人员提供必要的工具，以开展材料科学，凝聚态物理和光电器件工程领域的现代基础研究。由于设计的研究活动是高度跨学科的，学生将被激励采取跨学科的课程，如纳米科学，电子和扫描探针显微镜和纳米纤维。该计划旨在通过以下方式扩大学生的参与和理解：（a）将研究内容纳入本科生和研究生现有的纳米科学、纳米电子学和固态物理课程;（B）培训学生使用最先进的制作和表征工具，以及（c）让学生接触研究企业和不同组织的合作研究。2这项工作将导致培养一名博士生和几名本科生。通过高年级论文工作经验和科学研究俱乐部以及学院的开放日，向当地高中进行宣传，是为高中生攻读科学和工程学位做准备的过度策略的一部分。手征打破了空间反演对称性，并导致意想不到的新电子性质，特别是在降维系统中。在许多情况下，电子手性是由它出现的系统的特定结构促进的，无论是在原子尺度上还是在介观尺度上。最近，人们发现，一个被充分研究的宏观相关电子态，电荷密度波，也表现出手征性。该提案探讨了使用纳米尺寸的相反手性领域的机会，与畴壁作为存储器和逻辑units.In这个建议，我们将扩大的基本理解的动态性质的耦合的手征CDW与飞秒光扰动和纳秒电流脉冲的基本元素。系统在恢复平衡之前所经历的激发亚稳态的动力学可能包括非常规秩序，例如铁电性、CDW或超导性。这些现象的起源是存在各种类型的对称性破缺（TiSe 2中的反转对称性），从而产生简并基态。在低功率电子器件中存在利用这些亚稳态的机会。我们还将优化TiSe 2薄膜的生长，以实现高效的器件制造。将探讨应变和掺杂对手性CDW热力学的影响。

项目成果

Photoinduced chiral charge density wave in TiSe2

TiSe2 中的光致手性电荷密度波

• DOI: 10.1103/physrevb.105.054102
• 发表时间: 2022
• 期刊: Physical Review B
• 影响因子: 3.7
• 作者: Wickramaratne, Darshana;Subedi, Sujan;Torchinsky, Darius H.;Karapetrov, G.;Mazin, I. I.
• 通讯作者: Mazin, I. I.

Evidence for pseudo–Jahn-Teller distortions in the charge density wave phase of 1T−TiSe2

1T-TiSe2 电荷密度波相位中伪 Jahn-Teller 畸变的证据

• DOI: 10.1103/physrevb.101.195145
• 发表时间: 2020
• 期刊: Physical Review B
• 影响因子: 3.7
• 作者: Wegner, A.;Zhao, J.;Li, J.;Yang, J.;Anikin, A. A.;Karapetrov, G.;Esfarjani, K.;Louca, D.;Chatterjee, U.
• 通讯作者: Chatterjee, U.

Spontaneous gyrotropic electronic order in a transition-metal dichalcogenide

• DOI: 10.1038/s41586-020-2011-8
• 发表时间: 2019-10
• 期刊: Nature
• 影响因子: 64.8
• 作者: Su-Yang Xu;Q. Ma;Yang Gao;A. Kogar;A. Zong;Andrés M. Mier Valdivia;T. Dinh;Shin-Ming Huang