TY - JOUR
T1 - Coherence Between Different Propagating Surface Plasmon Polariton Modes Excited by Quantum Mechanical Tunnel Junctions
AU - Radulescu, Andreea
AU - Kalathingal, Vijith
AU - Wang, Zhe
AU - Nijhuis, Christian A.
N1 - Funding Information:
A.R. and V.K. contributed equally to this work. The authors acknowledge the National Research Foundation (NRF) for supporting this research under the Prime Minister's Office, Singapore, under its Medium Sized Centre Programme and the Competitive Research Programme (CRP) (NRF‐CRP17‐2017‐08). The authors also thank the Centre for Advanced 2D Materials (CA2DM) for the provided facilities. The authors would like to thank Dr. Thorin J. Duffin for fruitful discussions.
Publisher Copyright:
© 2021 The Authors. Advanced Optical Materials published by Wiley-VCH GmbH
PY - 2022/2/4
Y1 - 2022/2/4
N2 - Coherence between different surface plasmon polariton (SPP) modes excited by inelastically tunneling electrons in biased metal–insulator–metal tunnel junctions (MIM-TJs) is demonstrated. By employing a dedicated SPP stripe waveguide with MIM-TJ, an effective double-slit configuration similar to the Young's experiment is realized for an electrically biased SPP source. The spatial correlation between different SPP modes originates from a single inelastic tunneling event and leads to strong interference in the far-field, observed as alternate bright and dark fringes in the Fourier plane. The measured fringe-spacing inversely follows the stripe waveguide length, with upper limit dictated by the SPP propagation length, confirming the SPP mediated spatial correlation. Finite difference time domain simulations support the experimental findings. Also, the experimental and simulation results unambiguously demonstrate the two-step plasmonic decay process in plasmonic MIM-TJs. The results presented here provide a simple and robust demonstration of the inherent coherence existing between different decay channels (plasmons and photons) of the inelastically tunneling electrons and can be exploited for plasmonic applications with tailored spatial coherence with implications in plasmon amplification and quantum information processing.
AB - Coherence between different surface plasmon polariton (SPP) modes excited by inelastically tunneling electrons in biased metal–insulator–metal tunnel junctions (MIM-TJs) is demonstrated. By employing a dedicated SPP stripe waveguide with MIM-TJ, an effective double-slit configuration similar to the Young's experiment is realized for an electrically biased SPP source. The spatial correlation between different SPP modes originates from a single inelastic tunneling event and leads to strong interference in the far-field, observed as alternate bright and dark fringes in the Fourier plane. The measured fringe-spacing inversely follows the stripe waveguide length, with upper limit dictated by the SPP propagation length, confirming the SPP mediated spatial correlation. Finite difference time domain simulations support the experimental findings. Also, the experimental and simulation results unambiguously demonstrate the two-step plasmonic decay process in plasmonic MIM-TJs. The results presented here provide a simple and robust demonstration of the inherent coherence existing between different decay channels (plasmons and photons) of the inelastically tunneling electrons and can be exploited for plasmonic applications with tailored spatial coherence with implications in plasmon amplification and quantum information processing.
KW - back focal plane imaging
KW - coherent tunnel junctions
KW - electrical excitation of plasmons
KW - interference
KW - near-field coupling
KW - optical coherence
KW - UT-Hybrid-D
UR - http://www.scopus.com/inward/record.url?scp=85120813510&partnerID=8YFLogxK
U2 - 10.1002/adom.202101804
DO - 10.1002/adom.202101804
M3 - Article
AN - SCOPUS:85120813510
SN - 2195-1071
VL - 10
JO - Advanced Optical Materials
JF - Advanced Optical Materials
IS - 3
M1 - 2101804
ER -