%ADai, Siyuan [Materials Research and Education Center Department of Mechanical Engineering Auburn University Auburn AL 36849 USA]%AFang, Wenjing [Department of Electrical Engineering &, Computer Sciences Massachusetts Institute of Technology Cambridge MA 02139 USA]%ARivera, Nicholas [John A. Paulson School of Engineering and Applied Sciences Harvard University Cambridge MA 02139 USA, Department of Physics Massachusetts Institute of Technology Cambridge MA 02139 USA]%AStehle, Yijing [Sichuan University Pittsburgh Institute Sichuan University Sichuan Chengdu 610017 China]%AJiang, Bor‐Yuan [Department of Physics University of California, San Diego La Jolla CA 92093 USA]%AShen, Jialiang [Materials Research and Education Center Department of Mechanical Engineering Auburn University Auburn AL 36849 USA]%ATay, Roland [School of Electrical and Electronic Engineering Nanyang Technology University 50 Nanyang Avenue Singapore 639798 Singapore]%ACiccarino, Christopher [John A. Paulson School of Engineering and Applied Sciences Harvard University Cambridge MA 02139 USA]%AMa, Qiong [Department of Physics Massachusetts Institute of Technology Cambridge MA 02139 USA]%ARodan‐Legrain, Daniel [Department of Physics Massachusetts Institute of Technology Cambridge MA 02139 USA]%AJarillo‐Herrero, Pablo [Department of Physics Massachusetts Institute of Technology Cambridge MA 02139 USA]%ATeo, Edwin [School of Electrical and Electronic Engineering Nanyang Technology University 50 Nanyang Avenue Singapore 639798 Singapore]%AFogler, Michael [Department of Physics University of California, San Diego La Jolla CA 92093 USA]%ANarang, Prineha [John A. Paulson School of Engineering and Applied Sciences Harvard University Cambridge MA 02139 USA]%AKong, Jing [Department of Electrical Engineering &, Computer Sciences Massachusetts Institute of Technology Cambridge MA 02139 USA]%ABasov, Dimitri [Department of Physics Columbia University New York NY 10027 USA]%BJournal Name: Advanced Materials; Journal Volume: 31; Journal Issue: 37; Related Information: CHORUS Timestamp: 2023-09-09 12:16:50 %D2019%IWiley Blackwell (John Wiley & Sons) %JJournal Name: Advanced Materials; Journal Volume: 31; Journal Issue: 37; Related Information: CHORUS Timestamp: 2023-09-09 12:16:50 %K %MOSTI ID: 10114221 %PMedium: X %TPhonon Polaritons in Monolayers of Hexagonal Boron Nitride %XAbstract

Phonon polaritons in van der Waals materials reveal significant confinement accompanied with long propagation length: important virtues for tasks pertaining to the control of light and energy flow at the nanoscale. While previous studies of phonon polaritons have relied on relatively thick samples, here reported is the first observation of surface phonon polaritons in single atomic layers and bilayers of hexagonal boron nitride (hBN). Using antenna‐based near‐field microscopy, propagating surface phonon polaritons in mono‐ and bilayer hBN microcrystals are imaged. Phonon polaritons in monolayer hBN are confined in a volume about one million times smaller than the free‐space photons. Both the polariton dispersion and their wavelength–thickness scaling law are altered compared to those of hBN bulk counterparts. These changes are attributed to phonon hardening in monolayer‐thick crystals. The data reported here have bearing on applications of polaritons in metasurfaces and ultrathin optical elements.

%0Journal Article