TY  - JOUR
JF  - Nano Letters
A1  - Mitrofanov, O
SN  - 1530-6984
UR  - https://doi.org/10.1021/acs.nanolett.9b01623
N1  - This version is the author accepted manuscript. For information on re-use, please refer to the publisher?s terms and conditions.
IS  - 7
VL  - 19
SP  - 4620
KW  - Intersubband polariton
KW  -  near-field microscopy
KW  -  quantum well
KW  -  nanoantenna
KW  -  nano-FTIR
ID  - discovery10075995
N2  - 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 ?-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.
PB  - American Chemical Society
TI  - Observation of Intersubband Polaritons in a Single Nanoantenna Using Nano-FTIR Spectroscopy
EP  - 4626
AV  - public
Y1  - 2019/07/10/
ER  -