Haffner, Christian

Date: Thursday, February 1, 2024
Time: 15:00
Place: ETH Campus Hönggerberg, HPF G6
Host: Matteo Fadel

Thin-film strontium titanate for electro-optical transduction

Christan Haffner - IMEC, Belgium

Abstract: Quantum computers face many challenges towards upscaling the number of qubits and increasing their computational power. One of them is the radio frequency (RF) -bottleneck between the qubit processor inside the cryostat and the room temperature control and readout electronics. And like for their classical counterparts, hope lies in replacing the RF-links by optical fibers, resulting in a hybrid situation where RF-qubits will be used for computation and optical qubits will serve for remote communication. However, electro-optical (EO) transducers that parametrically amplify RF-qubits directly to optical qubits with a unity efficiency have thus far remained elusive. Key to a unity efficiency are materials that feature low losses, strong nonlinearities and that allow to squeeze down the electro-magnetic field to smallest volumes. Current research focuses on devices based on opto-electro-mechanics or on lithium niobate devices - the classical workhorse of long-range optical communication. In this talk, we discuss high-k strontium titanate as a potential new material that could provide nonlinearities larger than lithium niobate, its unique challenges for EO-transduction and our progress on thin-film integration.