Chiral phonons in SrCuTe₂O₆ via Raman scattering

Chirality plays a crucial role in various branches of chemistry and physics, manifesting properties important to catalysis, medicine, and photonics. In non-centrosymmetric crystals, phonons can exhibit chirality -  so called chiral phonons - characterized by elliptical displacement patterns that couple uniquely with circularly polarized light. In this work, we explore the vibrational properties of monochiral SrCuTe₂O₆, a material crystallizing in the P4₁32 space group, using Raman scattering spectroscopy. Owing to the lack of inversion symmetry and mirror planes, cubic SrCuTe₂O₆ is a promising platform for discovery chiral phonons and tunability under external stimuli. We find that the Cu chain drives most of the effects – at room temperature, where we uncover peak splittings in the CuO4 plaquette librations – to cryogenic temperatures, high magnetic fields, and even pressure, which modifies bond lengths and angles. These trends provide compelling evidence for the presence of chiral phonons and highlight the potential of cubic materials for exploring chiral dynamics in the solid state.