Observation of Intersubband Polaritons in a Single Nanoantenna Using Nano-FTIR Spectroscopy

Journal Article · Mon Jun 10 00:00:00 EDT 2019 · Nano Letters

DOI:https://doi.org/10.1021/acs.nanolett.9b01623· OSTI ID:1542853

Wang, Chih-Feng ^[1]; Habteyes, Terefe G. ^[2]; Luk, Ting Shan ^[3]; Klem, John F. ^[3]; Brener, Igal ^[4]; Chen, Hou-Tong ^[5]; Mitrofanov, Oleg ^[6]

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1. Univ. of New Mexico, Albuquerque, NM (United States); Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Center for Integrated Nanotechnologies (CINT)
2. Univ. of New Mexico, Albuquerque, NM (United States)
3. Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
4. Sandia National Lab. (SNL-CA), Livermore, CA (United States)
5. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
6. Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Univ. College London, London (United Kingdom)

Strong coupling of an intersubband (ISB) electron transition in quantum wells to a subwavelength plasmonic nanoantenna can give rise to intriguing quantum phenomena, such as ISB polariton condensation, and enable practical devices including low threshold lasers. However, experimental observation of ISB polaritons in an isolated subwavelength system has not yet been reported. Here, we use scanning probe near-field microscopy and Fourier-transform infrared (FTIR) spectroscopy to detect formation of ISB polariton states in a single nanoantenna. We excite the nanoantenna by a broadband IR pulse and spectrally analyze evanescent fields on the nanoantenna surface. We observe the distinctive splitting of the nanoantenna resonance peak into two polariton modes and two π-phase steps corresponding to each of the modes. We map ISB polariton dispersion using a set of nanoantennae of different sizes. This nano-FTIR spectroscopy approach opens doors for investigations of ISB polariton physics in the single subwavelength nanoantenna regime.

• Research Organization: Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22).
• Grant/Contract Number: 89233218CNA000001
• OSTI ID: 1542853
• Alternate ID(s): OSTI ID: 1559559; OSTI ID: 1570264
• Report Number(s): LA-UR--19-22652
• Journal Information: Nano Letters, Journal Name: Nano Letters Journal Issue: 7 Vol. 19; ISSN 1530-6984
• Publisher: American Chemical Society
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
77 NANOSCIENCE AND NANOTECHNOLOGY
Material Science