1. Optical Nanomaterial GroupInstitute for Quantum ElectronicsDepartment of PhysicsETH Zurich Auguste‐Piccard‐Hof 1 Zurich 8093 Switzerland
2. Laboratory for Multifunctional Ferroic MaterialsDepartment of MaterialsETH Zurich Vladimir‐Prelog‐Weg 4 8093 Zurich Switzerland