Layer-controlled nonlinear terahertz valleytronics in two-dimensional semimetal and semiconductor PtSe2

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61989100%3A27360%2F23%3A10252689" target="_blank" >RIV/61989100:27360/23:10252689 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/61989100:27640/23:10252689 RIV/61989100:27740/23:10252689

Výsledek na webu

<a href="https://onlinelibrary.wiley.com/doi/full/10.1002/inf2.12468" target="_blank" >https://onlinelibrary.wiley.com/doi/full/10.1002/inf2.12468</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1002/inf2.12468" target="_blank" >10.1002/inf2.12468</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Layer-controlled nonlinear terahertz valleytronics in two-dimensional semimetal and semiconductor PtSe2

Popis výsledku v původním jazyce

Platinum diselenide (PtSe2) is a promising two-dimensional (2D) material for the terahertz (THz) range as, unlike other transitionmetal dichalcogenides (TMDs), its bandgap can be uniquely tuned from a semiconductor in the near-infrared to a semimetal with thenumber of atomic layers. This gives the material unique THz photonic properties that can be layer-engineered. Here, we demonstratethat a controlled THz nonlinearity - tuned from monolayer to bulk PtSe2 - can be realised in wafer size polycrystalline PtSe2 throughthe generation of ultrafast photocurrents and the engineering of the bandstructure valleys. This is combined with the PtSe2 layerinteraction with the substrate for a broken material centro-symmetry permitting a second order nonlinearity. Further, we show layerdependent circular dichroism, where the sign of the ultrafast currents and hence the phase of the emitted THz pulse can be controlledthrough the excitation of different bandstructure valleys. In particular, we show that a semimetal has a strong dichroism that is absentin the monolayer and few layer semiconducting limit. The microscopic origins of this TMD bandstructure engineering is highlightedthrough detailed DFT simulations, and shows the circular dichroism can be controlled when PtSe2 becomes a semimetal and when theK-valleys can be excited. As well as showing that PtSe2 is a promising material for THz generation through layer controlled opticalnonlinearities, this work opens up new class of circular dichroism materials beyond the monolayer limit that has been the case oftraditional TMDs, and impacting a range of domains from THz valleytronics, THz spintronics to harmonic generation

Název v anglickém jazyce

Layer-controlled nonlinear terahertz valleytronics in two-dimensional semimetal and semiconductor PtSe2

Popis výsledku anglicky

Platinum diselenide (PtSe2) is a promising two-dimensional (2D) material for the terahertz (THz) range as, unlike other transitionmetal dichalcogenides (TMDs), its bandgap can be uniquely tuned from a semiconductor in the near-infrared to a semimetal with thenumber of atomic layers. This gives the material unique THz photonic properties that can be layer-engineered. Here, we demonstratethat a controlled THz nonlinearity - tuned from monolayer to bulk PtSe2 - can be realised in wafer size polycrystalline PtSe2 throughthe generation of ultrafast photocurrents and the engineering of the bandstructure valleys. This is combined with the PtSe2 layerinteraction with the substrate for a broken material centro-symmetry permitting a second order nonlinearity. Further, we show layerdependent circular dichroism, where the sign of the ultrafast currents and hence the phase of the emitted THz pulse can be controlledthrough the excitation of different bandstructure valleys. In particular, we show that a semimetal has a strong dichroism that is absentin the monolayer and few layer semiconducting limit. The microscopic origins of this TMD bandstructure engineering is highlightedthrough detailed DFT simulations, and shows the circular dichroism can be controlled when PtSe2 becomes a semimetal and when theK-valleys can be excited. As well as showing that PtSe2 is a promising material for THz generation through layer controlled opticalnonlinearities, this work opens up new class of circular dichroism materials beyond the monolayer limit that has been the case oftraditional TMDs, and impacting a range of domains from THz valleytronics, THz spintronics to harmonic generation

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10300 - Physical sciences

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

Infomat

ISSN

2567-3165

e-ISSN

—

Svazek periodika

5

Číslo periodika v rámci svazku

11

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

16

Strana od-do

—

Kód UT WoS článku

001061365300001

EID výsledku v databázi Scopus

2-s2.0-85169840330