TY - JOUR

T1 - Ultrafast quantum beats of anisotropic excitons in atomically thin ReS2

AU - Sim, Sangwan

AU - Lee, Doeon

AU - Trifonov, Artur V.

AU - Kim, Taeyoung

AU - Cha, Soonyoung

AU - Sung, Ji Ho

AU - Cho, Sungjun

AU - Shim, Wooyoung

AU - Jo, Moon Ho

AU - Choi, Hyunyong

N1 - Funding Information: A.V.T. acknowledges Saint Petersburg State University for a research grant 11.34.2.2012. S.S., J.H.S. and M.-H.J. were supported by Institute for Basic Science (IBS), Korea, under the Project Code (IBS-R014-G1-2016-a00). Funding Information: S.S., D.L., T.K., S.Cha., and H.C. were supported by the National Research Foundation of Korea (NRF) through the government of Korea (MSIP) (Grant Nos NRF-2015R1A2A1A10052520, NRF-2016R1A4A1012929), Global Frontier Program (2014M3A6B3063709). A.V.T. acknowledges Saint Petersburg State University for a research grant 11.34.2.2012. S.S., J.H.S. and M.-H.J. were supported by Institute for Basic Science (IBS), Korea, under the Project Code (IBS-R014-G1-2016-a00). Publisher Copyright: © 2018 The Author(s). Copyright: Copyright 2019 Elsevier B.V., All rights reserved.

PY - 2018/12/1

Y1 - 2018/12/1

N2 - Quantum beats, periodic oscillations arising from coherent superposition states, have enabled exploration of novel coherent phenomena. Originating from strong Coulomb interactions and reduced dielectric screening, two-dimensional transition metal dichalcogenides exhibit strongly bound excitons either in a single structure or hetero-counterpart; however, quantum coherence between excitons is barely known to date. Here we observe exciton quantum beats in atomically thin ReS2 and further modulate the intensity of the quantum beats signal. Surprisingly, linearly polarized excitons behave like a coherently coupled three-level system exhibiting quantum beats, even though they exhibit anisotropic exciton orientations and optical selection rules. Theoretical studies are also provided to clarify that the observed quantum beats originate from pure quantum coherence, not from classical interference. Furthermore, we modulate on/off quantum beats only by laser polarization. This work provides an ideal laboratory toward polarization-controlled exciton quantum beats in two-dimensional materials.

AB - Quantum beats, periodic oscillations arising from coherent superposition states, have enabled exploration of novel coherent phenomena. Originating from strong Coulomb interactions and reduced dielectric screening, two-dimensional transition metal dichalcogenides exhibit strongly bound excitons either in a single structure or hetero-counterpart; however, quantum coherence between excitons is barely known to date. Here we observe exciton quantum beats in atomically thin ReS2 and further modulate the intensity of the quantum beats signal. Surprisingly, linearly polarized excitons behave like a coherently coupled three-level system exhibiting quantum beats, even though they exhibit anisotropic exciton orientations and optical selection rules. Theoretical studies are also provided to clarify that the observed quantum beats originate from pure quantum coherence, not from classical interference. Furthermore, we modulate on/off quantum beats only by laser polarization. This work provides an ideal laboratory toward polarization-controlled exciton quantum beats in two-dimensional materials.

UR - http://www.scopus.com/inward/record.url?scp=85041089604&partnerID=8YFLogxK

U2 - 10.1038/s41467-017-02802-8

DO - 10.1038/s41467-017-02802-8

M3 - Article

C2 - 29367747

AN - SCOPUS:85041089604

VL - 9

JO - Nature Communications

JF - Nature Communications

SN - 2041-1723

IS - 1

M1 - 351

ER -