BROWSE

Related Scientist

Fukutani, Keisuke's photo.

Fukutani, Keisuke
원자제어 저차원 전자계 연구단
more info

ITEM VIEW & DOWNLOAD

Detecting photoelectrons from spontaneously formed excitons

Cited 0 time in webofscience Cited 0 time in scopus
21 Viewed 0 Downloaded
Title
Detecting photoelectrons from spontaneously formed excitons
Author(s)
Keisuke Fukutani; Roland Stania; Chang Il Kwon; Jun Sung Kim; Ki Jeong Kong; Jaeyoung Kim; Han Woong Yeom
Publication Date
2021-09
Journal
NATURE PHYSICS, v.17, no.9, pp.1024 - 1030
Publisher
NATURE RESEARCH
Abstract
Excitons have been predicted to form spontaneously-without external excitation-in some materials. Low-temperature ARPES measurements on Ta2NiSe5 now provide evidence for such an excitonic insulator and for so-called preformed excitons. Excitons, quasiparticles of electrons and holes bound by Coulombic attraction, are created transiently by light and play an important role in optoelectronics, photovoltaics and photosynthesis. They are also predicted to form spontaneously in a small-gap semiconductor or a semimetal, leading to a Bose-Einstein condensate at low temperature, but there has not been any direct evidence of this effect so far. Here we detect the photoemission signal from spontaneously formed excitons in a debated excitonic insulator candidate, Ta2NiSe5. Our symmetry-selective angle-resolved photoemission spectroscopy reveals a characteristic excitonic feature above the transition temperature, which provides detailed properties of excitons, such as the anisotropic Bohr radius. The present result provides evidence for so-called preformed excitons and guarantees the excitonic insulator nature of Ta2NiSe5 at low temperature.
URI
https://pr.ibs.re.kr/handle/8788114/10582
DOI
10.1038/s41567-021-01289-x
ISSN
1745-2473
Appears in Collections:
Center for Artificial Low Dimensional Electronic Systems(원자제어 저차원 전자계 연구단) > 1. Journal Papers (저널논문)
Files in This Item:
There are no files associated with this item.

qrcode

  • facebook

    twitter

  • Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.
해당 아이템을 이메일로 공유하기 원하시면 인증을 거치시기 바랍니다.

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.

Browse