Detector-Modulator Technology Utilizing Epsilon-Near-Zero Materials at Cryogenic Temperatures (D-TEC)

Basic data for this project

Description

Photonic integrated circuit implementations hold great promise for quantum technology, but practical large-scale integration is limited by the capabilities and performance of key components for processing and measuring quantum information, particularly phase-shifters and single-photon detectors. Current modulators fall short due to either high losses, large size, slow speed, energy inefficiency and/or excessive heat dissipation, making them incompatible with superconducting cryoelectronics. In the other hand, while superconducting detector technology has seen significant progress, their integration into photonic circuits lacks the flexibility needed for dynamic (mid-circuit measurements, feed-forward) reconfigurability, as detectors need to be placed at the output of the network and classical data is only being retrieved at the final stage. Project D-TEC, addresses these challenges by exploiting a novel class of electro-optic modulator for quantum photonics at cryogenic temperatures, featuring the epsilon-near- zero (ENZ) effect. Specifically, indium tin oxide-(ITO)-based electro-optic modulators show a strong ENZ effect, which enhances the local optical field and produces a large refractive index change near the ENZ wavelength. When operated at liquid helium temperatures, two significant effects occur simultaneously. First, ohmic losses of ITO material are reduced, amplifying the local-field enhancement of the ENZ effect to unprecedented levels. Second, ITO exhibits superconductivity at critical temperatures below 5 K. It thus becomes possible to create phase modulators with performance far beyond the state-of-the-art and a completely novel type of single photon detector, with tunable photon absorption capabilities. These innovations enable fast, cryo-compatible circuit reconfigurability and the possibility of introducing feed-forward and mid-circuit measurements, enabling a new dynamic quantum photonic computing paradigm with vast potential for scalability.