Ultrafast Hidden Spin Polarization Dynamics of Bright and Dark Excitons in 2H-WSe2

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F49777513%3A23640%2F23%3A43972158" target="_blank" >RIV/49777513:23640/23:43972158 - isvavai.cz</a>

Výsledek na webu

<a href="https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.131.066402" target="_blank" >https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.131.066402</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1103/PhysRevLett.131.066402" target="_blank" >10.1103/PhysRevLett.131.066402</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Ultrafast Hidden Spin Polarization Dynamics of Bright and Dark Excitons in 2H-WSe2

Popis výsledku v původním jazyce

We performed spin-, time- and angle- resolved extreme ultraviolet photoemission spectroscopy of excitons prepared by photoexcitation of inversion-symmetric 2H-WSe2 with circularly polarized light. The very short probing depth of XUV photoemission permits selective measurement of photoelectrons originating from the top-most WSe2 layer, allowing for direct measurement of hidden spin polarization of bright and momentum-forbidden dark excitons. Our results reveal efficient chiroptical control of bright excitons&apos; hidden spin polarization. Following optical photoexcitation, intervalley scattering between nonequivalent K-K &apos; valleys leads to a decay of bright excitons&apos; hidden spin polarization. Conversely, the ultrafast formation of momentum-forbidden dark excitons acts as a local spin polarization reservoir, which could be used for spin injection in van der Waals heterostructures involving multilayer transition metal dichalcogenides.

Název v anglickém jazyce

Ultrafast Hidden Spin Polarization Dynamics of Bright and Dark Excitons in 2H-WSe2

Popis výsledku anglicky

We performed spin-, time- and angle- resolved extreme ultraviolet photoemission spectroscopy of excitons prepared by photoexcitation of inversion-symmetric 2H-WSe2 with circularly polarized light. The very short probing depth of XUV photoemission permits selective measurement of photoelectrons originating from the top-most WSe2 layer, allowing for direct measurement of hidden spin polarization of bright and momentum-forbidden dark excitons. Our results reveal efficient chiroptical control of bright excitons&apos; hidden spin polarization. Following optical photoexcitation, intervalley scattering between nonequivalent K-K &apos; valleys leads to a decay of bright excitons&apos; hidden spin polarization. Conversely, the ultrafast formation of momentum-forbidden dark excitons acts as a local spin polarization reservoir, which could be used for spin injection in van der Waals heterostructures involving multilayer transition metal dichalcogenides.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10302 - Condensed matter physics (including formerly solid state physics, supercond.)

Projekt

—

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2023

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Physical Review Letters

ISSN

0031-9007

e-ISSN

1079-7114

Svazek periodika

131

Číslo periodika v rámci svazku

6

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

6

Strana od-do

—

Kód UT WoS článku

001162017900003

EID výsledku v databázi Scopus

2-s2.0-85168741166