2025/02/20 by Anja Ulrich, Ulrich, Anja, Kamal Brahim +28 · 1 citation
Engineering · #FOS: Physical sciences #Magneto-Optical Properties and Applications #Optics (physics.optics) #Photonic and Optical Devices #Quantum Physics (quant-ph) #Semiconductor Lasers and Optical Devices
paper · pdf · doi:10.48550/arxiv.2502.14349
openalex publication_date 2025/02/20 · openalex created_date 2025/02/22 · openalex updated_date 2026/08/01
Materials which exhibit the Pockels effect are notable for their strong electro-optic interaction and rapid response times and are therefore used extensively in classical electro-optic components for data and telecommunication applications. Yet many materials optimized for room-temperature operation see their Pockels coefficients at cryogenic temperatures significantly reduced - a major hurdle for emerging quantum technologies which have even more rigorous demands than their classical counterpart. A noted example is BaTiO3, which features the strongest effective Pockels coefficient at room temperature, only to see it reduced to a third (i.e. \mathrmreff ≈ 170 pm/V) at a few Kelvin. Here, we show that this behaviour is not inherent and can even be reversed: Strontium titanate (SrTiO3), a material normally not featuring a Pockels coefficient, can be engineered to exhibit an \mathrmreff of 345 pm/V at cryogenic temperatures - a record value in any thin-film electro-optic material. By adjusting the stoichiometry, we can increase the Curie temperature and realise a ferroelectric phase that yields a high Pockels coefficient, yet with limited optical losses - on the order of decibels per centimetre. Our findings position SrTiO3 as one of the most promising materials for cryogenic quantum photonics applications.