Polymorphic gallium for active resonance tuning in photonic nanostructures: from bulk gallium to two-dimensional (2D) gallenene

Nanophotonics

article

Yael Gutiérrez¹  Pablo García-Fernández²  Javier Junquera²  April S. Brown³  Fernando Moreno²  Maria Losurdo¹ 

[1] Institute of Nanotechnology;Universidad de Cantabria;Department of Electrical and Computer Engineering, Duke University

关键词: active plasmonics;    gallenene;    gallium;    phase-change materials;    reconfigurable plasmonics;   

DOI  :  10.1515/nanoph-2020-0314

学科分类：社会科学、人文和艺术（综合）

来源: De Gruyter

【 摘 要 】

Reconfigurable plasmonics is driving an extensive quest for active materials that can support a controllable modulation of their optical properties for dynamically tunable plasmonic structures. Here, polymorphic gallium (Ga) is demonstrated to be a very promising candidate for adaptive plasmonics and reconfigurable photonics applications. The Ga sp -metal is widely known as a liquid metal at room temperature. In addition to the many other compelling attributes of nanostructured Ga, including minimal oxidation and biocompatibility, its six phases have varying degrees of metallic character, providing a wide gamut of electrical conductivity and optical behavior tunability. Here, the dielectric function of the several Ga phases is introduced and correlated with their respective electronic structures. The key conditions for optimal optical modulation and switching for each Ga phase are evaluated. Additionally, we provide a comparison of Ga with other more common phase-change materials, showing better performance of Ga at optical frequencies. Furthermore, we first report, to the best of our knowledge, the optical properties of liquid Ga in the terahertz (THz) range showing its broad plasmonic tunability from ultraviolet to visible-infrared and down to the THz regime. Finally, we provide both computational and experimental evidence of extension of Ga polymorphism to bidimensional two-dimensional (2D) gallenene, paving the way to new bidimensional reconfigurable plasmonic platforms.

【 授权许可】

CC BY