Title: Valley-selective optical Stark effect of exciton-polaritons in a monolayer semiconductor

Abstract

Selective breaking of degenerate energy levels is a well-known tool for coherent manipulation of spin states. Though most simply achieved with magnetic fields, polarization-sensitive optical methods provide high-speed alternatives. Exploiting the optical selection rules of transition metal dichalcogenide monolayers, the optical Stark effect allows for ultrafast manipulation of valley-coherent excitons. Compared to excitons in these materials, microcavity exciton-polaritons offer a promising alternative for valley manipulation, with longer lifetimes, enhanced valley coherence, and operation across wider temperature ranges. Here, we show valley-selective control of polariton energies in WS₂ using the optical Stark effect, extending coherent valley manipulation to the hybrid light-matter regime. Ultrafast pump-probe measurements reveal polariton spectra with strong polarization contrast originating from valley-selective energy shifts. This demonstration of valley degeneracy breaking at picosecond timescales establishes a method for coherent control of valley phenomena in exciton-polaritons.

Authors:

LaMountain, Trevor ^[1]; Nelson, Jovan ^[1]; Lenferink, Erik J. ^[2]; Amsterdam, Samuel H. ^[3]; Murthy, Akshay A.  ^[4];

• Search DOE PAGES for author "Murthy, Akshay A."
• Search DOE PAGES for ORCID "0000-0001-7677-6866"
• Search orcid.org for ORCID "0000-0001-7677-6866"

Zeng, Hongfei ^[2]; Marks, Tobin J.  ^[5];

• Search DOE PAGES for author "Marks, Tobin J."
• Search DOE PAGES for ORCID "0000-0001-8771-0141"
• Search orcid.org for ORCID "0000-0001-8771-0141"

Dravid, Vinayak P.  ^[6];

• Search DOE PAGES for author "Dravid, Vinayak P."
• Search DOE PAGES for ORCID "0000-0002-6007-3063"
• Search orcid.org for ORCID "0000-0002-6007-3063"

Hersam, Mark C.  ^[7];

• Search DOE PAGES for author "Hersam, Mark C."
• Search DOE PAGES for ORCID "0000-0003-4120-1426"
• Search orcid.org for ORCID "0000-0003-4120-1426"

Stern, Nathaniel P.  ^[8]

• Search DOE PAGES for author "Stern, Nathaniel P."
• Search DOE PAGES for ORCID "0000-0002-8903-3516"
• Search orcid.org for ORCID "0000-0002-8903-3516"

---

+ Show Author Affiliations

1. Northwestern Univ., Evanston, IL (United States). Applied Physics Program
2. Northwestern Univ., Evanston, IL (United States). Dept. of Physics and Astronomy
3. Northwestern Univ., Evanston, IL (United States). Dept. of Chemistry and the Materials Research Center
4. Northwestern Univ., Evanston, IL (United States). The Materials Research Center. Dept. of Materials Science and Engineering, International Inst. of Nanotechnology
5. Northwestern Univ., Evanston, IL (United States). Dept. of Chemistry and the Materials Research Center, The Materials Research Center. Dept. of Materials Science and Engineering
6. Northwestern Univ., Evanston, IL (United States). The Materials Research Center. Dept. of Materials Science and Engineering, International Inst. of Nanotechnology, NUANCE Center
7. Northwestern Univ., Evanston, IL (United States). Applied Physics Program, Dept. of Chemistry and the Materials Research Center, The Materials Research Center. Dept. of Materials Science and Engineering, Dept. of Electrical and Computer Engineering
8. Northwestern Univ., Evanston, IL (United States). Applied Physics Program, Dept. of Physics and Astronomy

Publication Date:

2021-07-26

Research Org.:

Northwestern Univ., Evanston, IL (United States)

Sponsoring Org.:

USDOE Office of Science (SC), Basic Energy Sciences (BES). Materials Sciences & Engineering Division

OSTI Identifier:

1816670

Grant/Contract Number:  

SC0012130

Resource Type:

Accepted Manuscript

Journal Name:

Nature Communications

Additional Journal Information:

Journal Volume: 12; Journal Issue: 1; Journal ID: ISSN 2041-1723

Publisher:

Nature Publishing Group

Country of Publication:

United States

Language:

English

Subject:

36 MATERIALS SCIENCE; 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY