On-chip filter bank spectroscopy at 600-700 GHz using NbTiN superconducting resonators

TL;DR

This paper demonstrates an on-chip submillimeter wave filter bank spectrometer operating at 600-700 GHz using NbTiN superconducting microresonators, achieving high-frequency resolution for potential applications in quantum electrodynamics and photodetectors.

Contribution

It introduces a novel on-chip filter bank spectrometer at unprecedented high frequencies using NbTiN superconducting resonators, expanding the operational range for submillimeter wave spectroscopy.

Findings

Resonance frequencies range from 614 to 685 GHz.

Frequency resolution decreases from 350 to 140 with increasing frequency.

Resonator dissipation likely limits the resolution at higher frequencies.

Abstract

We experimentally demonstrate the principle of an on-chip submillimeter wave filter bank spectrometer, using superconducting microresonators as narrow band-separation filters. The filters are made of NbTiN/SiNx/NbTiN microstrip line resonators, which have a resonance frequency in the range of 614-685 GHz---two orders of magnitude higher in frequency than what is currently studied for use in circuit quantum electrodynamics and photodetectors. The frequency resolution of the filters decreases from 350 to 140 with increasing frequency, most likely limited by dissipation of the resonators.