mireabulletinRussian Technological JournalRussian Technological Journal2782-32102500-316XRTU MIREA10.32362/2500-316X-2019-7-4-71-80mireabulletin-165Research ArticleМИКРО- И НАНОЭЛЕКТРОНИКА. ФИЗИКА КОНДЕНСИРОВАННОГО СОСТОЯНИЯMICRO- AND NANOELECTRONICS. CONDENSED MATTER PHYSICSКомплексный показатель преломления титаната стронция в терагерцовом диапазоне частотComplex Refractive Index of Strontium Titanate in the Terahertz Frequency Rangehttps://orcid.org/0000-0002-3013-8655БилыкВ. Р.BilykV. R.

аспирант кафедры наноэлектроники Физико-технологического института ; стажер-исследователь специализированной учебно-научной лаборатории сверхбыстрой динамики ферроиков кафедры наноэлектроники ФТИ 

119454, Россия, Москва, пр-т Вернадского, д. 78

Scopus Author ID: 57194048515

ResearcherID: N-9662-2015, https://orcid.org/

Postgraduate Student of the Chair of Nanoelectronics, Institute of Physics and Technology; researcher, Laboratory of UltrafastDynamics of Ferroics of the Chair of Nanoelectronics

78, Vernadskogo pr., Moscow 119454, Russia

Scopus Author ID: 57194048515

ResearcherID: N-9662-2015

vrbilyk@mail.ruhttps://orcid.org/0000-0001-9523-355XГришунинК. А.GrishuninK. A.

аспирант кафедры наноэлектроники Физико-технологического института

Scopus Author ID: 56968091600

ResearcherID: Q-1005-2017

119454, Россия, Москва, пр-т Вернадского, д. 78

Postgraduate Student of the Chair of Nanoelectronics, Institute of Physics and Technology

78, Vernadskogo pr., Moscow 119454, Russia

Scopus Author ID: 56968091600

ResearcherID: Q-1005-2017

ФГБОУ ВО «МИРЭА – Российский технологический университет» (РТУ МИРЭА)РоссияMIREA – Russian Technological University (RTU MIREA)Russian Federation201910082019747180Copyright © Билык В.Р., Гришунин К.А., 20192019Билык В.Р., Гришунин К.А.Bilyk V.R., Grishunin K.A.Данная работа распространяется под лицензией Creative Commons Attribution 4.0.This work is licensed under a Creative Commons Attribution 4.0 License.https://www.rtj-mirea.ru/jour/article/view/165

Современное развитие терагерцовой спектроскопии во временной области (THz-TDS) позволяет проводить более точные и достоверные измерения диэлектрических свойств по сравнению с традиционной инфракрасной спектроскопией с использованием некогерентного источника света. Широкополосная THz-TDS является мощным инструментом для определения действительной и мнимой частей комплексной диэлектрической проницаемости при прохождении ТГц-излучения, которая позволяет определять параметры мягких мод в сегнетоэлектриках. В данной работе методом терагерцовой спектроскопии с временным разрешением исследована зависимость комплексного показателя преломления монокристаллического квантового параэлетрика титаната стронция в терагерцовом диапазоне частот от 0.3 до 1.3 ТГц. Показано, что низкочастотный терагерцовый отклик материала обусловлен доминированием мягкой фононной моды TO1. Измеренные экспериментальные зависимости показали хорошее сходство с теоретическими кривыми, полученными из анализа модели осциллятора Лоренца для комплексной диэлектрической проницаемости титаната стронция. Результаты работы важны для понимания принципиальной возможности возбуждения параметра порядка в сегнетоэлектрических материалах и могут быть использованы для создания энергоэффективных устройств памяти со скоростью записи информации, близкой к теоретическому пределу.

The recent progress in terahertz time-domain spectroscopy enables the accurate and reliable measurements of dielectric properties in comparison with the traditional far-infrared spectroscopy using an incoherent light source. The broadband THz-TDS is a powerful tool to determine the real and imaginary parts of a complex dielectric constant by the transmission which allows to detect the parameters of the soft modes in ferroelectrics. In this work, the terahertz time-domain spectroscopy was used to investigate the dependence of the complex refractive index of a single-crystal quantum paraelectric strontium titanate in the terahertz frequency range from 0.3 to 2 THz. It was shown that the low-frequency terahertz response of the material is determined by the soft phonon mode TO1. The measured experimental dependences showed a good agreement with the theoretical curves obtained from the analysis of the Lorentz oscillator model for the complex dielectric constant of strontium titanate. The obtained results are necessary for understanding the principle of possibility to manipulate the order parameter in ferroelectric materials and can be used to create energy-efficient memory devices with a speed of recording information close to the theoretical limit.

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