Investigating the influence of conical intersections on the opto-electronic properties of solid-state defects used for novel types of quantum technologies.

• Applicant: Dr. Ronald Ulbricht
• Subject Area: Experimental Condensed Matter Physics ; Physical Chemistry of Molecules, Liquids and Interfaces, Biophysical Chemistry
• Term: from 2017 to 2019
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 337516874

Solid-state defects in materials such as diamond and silicon carbide, their most famous example being the nitrogen-vacancy centre in diamond, have become a popular playground to harness quantum effects for a variety of applications in quantum information and quantum cryptography, as well as nanoscale magnetic field and temperature sensors, biological markers and single-photon emitters.The herein proposed work sets out to investigate the influence of so-called conical intersections on specific opto-electronic properties of three prominent defects by using ultrafast spectroscopic techniques, i.e. experiments utilising femtosecond laser pulses. Conical intersections are a common phenomenon in molecules and are known to be responsible for exceptionally fast photochemical reactions. Such conical intersections can also exist in defects, yet their impact on defect properties have so far been neglected.The underlying concept follows an interdisciplinary approach by introducing experimental techniques commonly applied in molecular spectroscopy to the field of solid-state defects, in order to study electronic and vibrational dynamics that are influenced by conical intersections. The experimental methods include transient absorption spectroscopy, femtosecond stimulated Raman spectroscopy and two-dimensional coherent spectroscopy.

• DFG Programme: Research Fellowships
• International Connection: Singapore
• Host: Professor Dr. Zhi-Heng Loh