Energy Spectrum of Two-Dimensional Excitons in a Nonuniform Dielectric Medium

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216305%3A26620%2F19%3APU133731" target="_blank" >RIV/00216305:26620/19:PU133731 - isvavai.cz</a>

Výsledek na webu

<a href="https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.123.136801" target="_blank" >https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.123.136801</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1103/PhysRevLett.123.136801" target="_blank" >10.1103/PhysRevLett.123.136801</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Energy Spectrum of Two-Dimensional Excitons in a Nonuniform Dielectric Medium

Popis výsledku v původním jazyce

We demonstrate that, in monolayers (MLs) of semiconducting transition metal dichalcogenides, the s-type Rydberg series of excitonic states follows a simple energy ladder: ϵn ¼ −Ry=ðn þ δÞ2, n ¼ 1; 2;…, in which Ry is very close to the Rydberg energy scaled by the dielectric constant of the medium surrounding the ML and by the reduced effective electron-hole mass, whereas the ML polarizability is accounted for only by δ. This is justified by the analysis of experimental data on excitonic resonances, as extracted from magneto-optical measurements of a high-quality WSe2 ML encapsulated in hexagonal boron nitride (hBN), and well reproduced with an analytically solvable Schrödinger equation when approximating the electron-hole potential in the form of a modified Kratzer potential. Applying our convention to other MoSe2, WS2, MoS2 MLs encapsulated in hBN, we estimate an apparent magnitude of δ for each of the studied structures. Intriguingly, δ is found to be close to zero for WSe2 as well as for MoS2 monolayers, what implies that the energy ladder of excitonic states in these twodimensional structures resembles that of Rydberg states of a three-dimensional hydrogen atom.

Název v anglickém jazyce

Energy Spectrum of Two-Dimensional Excitons in a Nonuniform Dielectric Medium

Popis výsledku anglicky

We demonstrate that, in monolayers (MLs) of semiconducting transition metal dichalcogenides, the s-type Rydberg series of excitonic states follows a simple energy ladder: ϵn ¼ −Ry=ðn þ δÞ2, n ¼ 1; 2;…, in which Ry is very close to the Rydberg energy scaled by the dielectric constant of the medium surrounding the ML and by the reduced effective electron-hole mass, whereas the ML polarizability is accounted for only by δ. This is justified by the analysis of experimental data on excitonic resonances, as extracted from magneto-optical measurements of a high-quality WSe2 ML encapsulated in hexagonal boron nitride (hBN), and well reproduced with an analytically solvable Schrödinger equation when approximating the electron-hole potential in the form of a modified Kratzer potential. Applying our convention to other MoSe2, WS2, MoS2 MLs encapsulated in hBN, we estimate an apparent magnitude of δ for each of the studied structures. Intriguingly, δ is found to be close to zero for WSe2 as well as for MoS2 monolayers, what implies that the energy ladder of excitonic states in these twodimensional structures resembles that of Rydberg states of a three-dimensional hydrogen atom.

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

<a href="/cs/project/LQ1601" target="_blank" >LQ1601: CEITEC 2020</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2019

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

123

Číslo periodika v rámci svazku

13

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

6

Strana od-do

„136801-1“-„136801-6“

Kód UT WoS článku

000487744600008

EID výsledku v databázi Scopus

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