Exciton-driven antiferromagnetic metal in a correlated van der Waals insulator

被引：76

作者：

Belvin, Carina A. ^{[1
]}

Baldini, Edoardo ^{[1
]}

Ozel, Ilkem Ozge ^{[1
]}

Mao, Dan ^{[1
]}

Po, Hoi Chun ^{[1
]}

Allington, Clifford J. ^{[1
]}

Son, Suhan ^{[2
,3
]}

Kim, Beom Hyun ^{[4
]}

Kim, Jonghyeon ^{[5
]}

Hwang, Inho ^{[2
,3
]}

Kim, Jae Hoon ^{[5
]}

Park, Je-Geun ^{[2
,3
]}

Senthil, T. ^{[1
]}

Gedik, Nuh ^{[1
]}

机构：

[1] MIT, Dept Phys, Cambridge, MA 02139 USA

[2] Inst for Basic Sci Korea, Ctr Correlated Electron Syst, Seoul, South Korea

[3] Seoul Natl Univ, Ctr Quantum Mat, Dept Phys & Astron, Seoul, South Korea

[4] Korea Inst Adv Study, Seoul, South Korea

[5] Yonsei Univ, Dept Phys, Seoul, South Korea

来源：

NATURE COMMUNICATIONS | 2021年 / 12卷 / 01期

基金：

新加坡国家研究基金会; 瑞士国家科学基金会; 美国国家科学基金会;

关键词：

PHOTOCONDUCTIVITY; TRANSIENT;

D O I：

10.1038/s41467-021-25164-8

中图分类号：

O [数理科学和化学]; P [天文学、地球科学]; Q [生物科学]; N [自然科学总论];

学科分类号：

07 ; 0710 ; 09 ;

摘要：

Previous work has shown the existence of spin-orbit-entangled excitons and their coupling to antiferromagnetism in the correlated insulator NiPS3. Here the authors show that non-equilibrium driving of these excitons produces a transient metallic antiferromagnetic state that cannot be achieved by tuning the temperature in equilibrium. Collective excitations of bound electron-hole pairs-known as excitons-are ubiquitous in condensed matter, emerging in systems as diverse as band semiconductors, molecular crystals, and proteins. Recently, their existence in strongly correlated electron materials has attracted increasing interest due to the excitons' unique coupling to spin and orbital degrees of freedom. The non-equilibrium driving of such dressed quasiparticles offers a promising platform for realizing unconventional many-body phenomena and phases beyond thermodynamic equilibrium. Here, we achieve this in the van der Waals correlated insulator NiPS3 by photoexciting its newly discovered spin-orbit-entangled excitons that arise from Zhang-Rice states. By monitoring the time evolution of the terahertz conductivity, we observe the coexistence of itinerant carriers produced by exciton dissociation and a long-wavelength antiferromagnetic magnon that coherently precesses in time. These results demonstrate the emergence of a transient metallic state that preserves long-range antiferromagnetism, a phase that cannot be reached by simply tuning the temperature. More broadly, our findings open an avenue toward the exciton-mediated optical manipulation of magnetism.

引用

页数：7

共 30 条

[1] Ultrafast Spin Dynamics in Photodoped Spin-Orbit Mott Insulator Sr2IrO4 [J].