Spin coherence transfer in photogenerated multi-spin systems

• Applicant: Dr. Sabine Richert
• Subject Area: Physical Chemistry of Molecules, Liquids and Interfaces, Biophysical Chemistry
• Term: since 2019
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 417643975

A fundamental understanding of the factors controlling the spin dynamics in organicmulti-spin systems is essential to the development of organic spintronic devices and could provide a basis for the development of new quantum computing and information processing strategies. To be able to control the spin dynamics and thus the transfer of quantum information on a molecular level, the structure-function relationships in organic systems that can create, store, and transfer spin information need to be studied in a systematic way. Since quantum algorithms can only be executed if the information transfer in a quantum circuit remains coherent at all times, the question of how to generate, preserve and transfer spin coherence is central to these types of investigations.Within this project we propose to investigate spin information transfer in a variety of covalently linked organic chromophore−radical systems using electron paramagnetic resonance (EPR) spectroscopy. Photoexcitation of the chromophores produces well-defined initial spin states, while modern pulse EPR techniques provide a powerful means of manipulating and examining these states.Using a combination of EPR and optical spectroscopy we will (i) explore and establish pulse EPR methodology for the characterisation of spin information transfer in photogenerated multi-spin systems and (ii) explore the factors determining (a) coherence transfer and (b) coherence dephasing. The proposed studies aim at establishing a link between the molecular properties of the chromophore−radical system and its ability to transfer and store spin information efficiently. Being able to establish such a link would be the first step towards revolutionising the newly emerging field of molecular spintronics, which holds great promise for future developments and applications.

• DFG Programme: Independent Junior Research Groups
• International Connection: USA
• Major Instrumentation: Abstimmbares Lasersystem ; Arbitrary Waveform Generator (AWG) ; Q-Band TWT ; X-Band TWT
• Instrumentation Group: 1770 Elektronenspinresonanz-Spektrometer (EPR, ESR) ; 5700 Festkörper-Laser ; 6300 Meßgeneratoren, Meßsender, Frequenznormale
• Cooperation Partners: Professor Michael J. Therien, Ph.D.; Professor Dr. Michael R. Wasielewski