skip to main content
DOE PAGES title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Phonon Polaritonics in Two-Dimensional Materials

Abstract

Extreme confinement of electromagnetic energy by phonon polaritons holds the promise of strong and new forms of control over the dynamics of matter. To bring such control to the atomic-scale limit, it is important to consider phonon polaritons in two-dimensional (2D) systems. Recent studies have pointed out that in 2D, splitting between longitudinal and transverse optical (LO and TO) phonons is absent at the Γ point, even for polar materials. Does this lack of LO–TO splitting imply the absence of a phonon polariton in polar monolayers? To answer this, we connect the microscopic phonon properties with the macroscopic electromagnetic response. Specifically, we derive a first-principles expression for the conductivity of a polar monolayer specified by the wave-vector-dependent LO and TO phonon dispersions. In the long-wavelength (local) limit, we find a universal form for the conductivity in terms of the LO phonon frequency at the Γ point, its lifetime, and the group velocity of the LO phonon. Our analysis reveals that the phonon polariton of 2D is simply the LO phonon of the 2D system. For the specific example of hexagonal boron nitride (hBN), we estimate the confinement and propagation losses of the LO phonons, finding that high confinement and reasonablemore » propagation quality factors coincide in regions that may be difficult to detect with current near-field optical microscopy techniques. Finally, we study the interaction of external emitters with 2D hBN nanostructures, finding an extreme enhancement of spontaneous emission due to coupling with localized 2D phonon polaritons and the possibility of multimode strong and ultrastrong coupling between an external emitter and hBN phonons. This may lead to the design of new hybrid states of electrons and phonons based on strong coupling.« less

Authors:
ORCiD logo [1];  [2]; ORCiD logo [3]
  1. Harvard Univ., Cambridge, MA (United States); Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)
  2. Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)
  3. Harvard Univ., Cambridge, MA (United States)
Publication Date:
Research Org.:
Energy Frontier Research Centers (EFRC) (United States). Photonics at Thermodynamic Limits (PTL); Krell Institute, Ames, IA (United States); Stanford Univ., CA (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES)
OSTI Identifier:
1566555
Grant/Contract Number:  
FG02-97ER25308; SC0019140
Resource Type:
Accepted Manuscript
Journal Name:
Nano Letters
Additional Journal Information:
Journal Volume: 19; Journal Issue: 4; Journal ID: ISSN 1530-6984
Publisher:
American Chemical Society
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; optics, phonons; thermal conductivity; charge transport; materials and chemistry by design; mesostructured materials; synthesis (novel materials)

Citation Formats

Rivera, Nicholas, Christensen, Thomas, and Narang, Prineha. Phonon Polaritonics in Two-Dimensional Materials. United States: N. p., 2019. Web. https://doi.org/10.1021/acs.nanolett.9b00518.
Rivera, Nicholas, Christensen, Thomas, & Narang, Prineha. Phonon Polaritonics in Two-Dimensional Materials. United States. https://doi.org/10.1021/acs.nanolett.9b00518
Rivera, Nicholas, Christensen, Thomas, and Narang, Prineha. Thu . "Phonon Polaritonics in Two-Dimensional Materials". United States. https://doi.org/10.1021/acs.nanolett.9b00518. https://www.osti.gov/servlets/purl/1566555.
@article{osti_1566555,
title = {Phonon Polaritonics in Two-Dimensional Materials},
author = {Rivera, Nicholas and Christensen, Thomas and Narang, Prineha},
abstractNote = {Extreme confinement of electromagnetic energy by phonon polaritons holds the promise of strong and new forms of control over the dynamics of matter. To bring such control to the atomic-scale limit, it is important to consider phonon polaritons in two-dimensional (2D) systems. Recent studies have pointed out that in 2D, splitting between longitudinal and transverse optical (LO and TO) phonons is absent at the Γ point, even for polar materials. Does this lack of LO–TO splitting imply the absence of a phonon polariton in polar monolayers? To answer this, we connect the microscopic phonon properties with the macroscopic electromagnetic response. Specifically, we derive a first-principles expression for the conductivity of a polar monolayer specified by the wave-vector-dependent LO and TO phonon dispersions. In the long-wavelength (local) limit, we find a universal form for the conductivity in terms of the LO phonon frequency at the Γ point, its lifetime, and the group velocity of the LO phonon. Our analysis reveals that the phonon polariton of 2D is simply the LO phonon of the 2D system. For the specific example of hexagonal boron nitride (hBN), we estimate the confinement and propagation losses of the LO phonons, finding that high confinement and reasonable propagation quality factors coincide in regions that may be difficult to detect with current near-field optical microscopy techniques. Finally, we study the interaction of external emitters with 2D hBN nanostructures, finding an extreme enhancement of spontaneous emission due to coupling with localized 2D phonon polaritons and the possibility of multimode strong and ultrastrong coupling between an external emitter and hBN phonons. This may lead to the design of new hybrid states of electrons and phonons based on strong coupling.},
doi = {10.1021/acs.nanolett.9b00518},
journal = {Nano Letters},
number = 4,
volume = 19,
place = {United States},
year = {2019},
month = {3}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record

Citation Metrics:
Cited by: 8 works
Citation information provided by
Web of Science

Save / Share:

Works referencing / citing this record:

Polariton Photonics Using Structured Metals and 2D Materials
journal, October 2019

  • Cai, Ziqiang; Xu, Yihao; Wang, Chuangtang
  • Advanced Optical Materials, Vol. 8, Issue 5
  • DOI: 10.1002/adom.201901090

Probing Polaritons in 2D Materials with Synchrotron Infrared Nanospectroscopy
journal, December 2019

  • Barcelos, Ingrid D.; Bechtel, Hans A.; de Matos, Christiano J. S.
  • Advanced Optical Materials, Vol. 8, Issue 5
  • DOI: 10.1002/adom.201901091

Three-dimensional near-field analysis through peak force scattering-type near-field optical microscopy
journal, January 2020

  • Wang, Haomin; Li, Jiahan; Edgar, James H.
  • Nanoscale, Vol. 12, Issue 3
  • DOI: 10.1039/c9nr08417g