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7Photodetectors based on 2D superconducting NbSe2 films integrated on silicon nitride waveguide
K.V. Shein12, E. Zharkov3, A. Lyubchak12, G.N. Goltsman1'2, I. Charaev4, D.A. Bandurin5,
I. Gayduchenko12*
1-National Research University Higher School of Economics, Moscow, Russia, 101000 2- Moscow Pedagogical State University, Moscow, Russia, 119435 3- Programmable Functional Materials Lab, Brain and Consciousness Research Center, Moscow, Russia,
121205
4- University of Zürich, Zürich, Switzerland, 8057 5- Department of Materials Science and Engineering, National University of Singapore, Singapore, 117575
Photonic integrated circuits (PICs) represent a promising platform for quantum technologies such as quantum computing and cryptography. One of the key components of such systems is a detector based on thin superconducting films. Despite the successful demonstration of superconducting detectors in planar geometry, their integration on waveguides in the form of thin superconducting films of the same quality remains technologically challenging. As an alternative approach, in this work we present the concept of an on-chip superconducting detector based on a two-dimensional mechanically exfoliated superconductor. The advantages of this approach are the ease of integration of the device on the waveguide, as well as the possibility of a single-layer detector thickness.
Niobium diselenide (NbSe2) is a promising material for creating superconducting waveguide detectors due to its superconducting properties up to the monolayer limit. Moreover, NbSe2 has already demonstrated sensitivity as a detector in the terahertz [1] and near-IR [2] ranges. In this work, we demonstrate an hBN/NbSe2/hBN photodetector integrated on silicon waveguide. We first simulate the absorption of electromagnetic radiation by hBN/NbSe2/hBN flakes on silicon waveguide to optimize the photodetector geometry. Based on the simulation results, it is proposed to integrate photodetector on silicon microring resonator to enhance the absorption of electromagnetic radiation. Next, we develop technological route for manufacturing the device, including the transfer of 2D superconductor on the waveguide, the formation of low-resistance contacts and the patterning of NbSe2 films. Finally, we demonstrate the strong bolometric response of the fabricated device in the visible and near-infrared regions. The results provide the basis for prototyping fully integrated quantum photonic integrated circuits.
This work was financially supported by RSF (project No. 23-72-00014).
[1] Y. Meng, et al, Photonic van der Waals integration from 2D materials to 3D nanomembranes, Nat Rev Mater, 8, 498-517 (2023).
[2] K. Shein, et al, Fundamental Limits of Few-Layer NbSe2 Microbolometers at Terahertz Frequencies, Nano Letters, 24 (7), 2282-2288 (2024).
