Controlling electronic spin and chirality in organic semiconductors

by Mr Rituparno Chowdhury (The Cavendish Laboratory, University of Cambridge, UK)

Wednesday 8 Jan 2025, 14:30 → 16:30 Asia/Kolkata

AG 80 (TIFR, Mumbai )

Controlling electronic spin is widely considered as the most promising means of achieving quantum computation. Gaining this degree-of-freedom in a well-understood and characterised semiconductor, organic and inorganic, remains elusive. I show a set of breakthroughs1,2, which forms the core tenets of my research, are capable of reading, writing and manipulating spin-states within organic semiconductors. First1, I show that through the use a unique chemical design of organic diradicals that allows us to perform optical ‘read and write’ of the ground-state spin populations, akin to the NV-center in diamond. Secondly2, I show that we can construct chirally-stacked columns using an organic semiconductor to deposit vacuum-sublimed films capable of producing circularly polarized electroluminescence and filtering electronic spin in the presence of a magnetic field. These properties are afforded by the chiral induced spin-selectivity, CISS, effect in these chiral semiconductors. The over-arching goal of my presented advancements is to show that organic semiconductors provide a very potent set of options for spin control and quantum computation. References 1. Chowdhury, Rituparno, et al. "Circularly polarised electroluminescence from chiral excitons in vacuum-sublimed supramolecular semiconductor thin films." arXiv preprint arXiv:2408.13905 (2024). Under Review. 2. Chowdhury, Rituparno, et al. "Optical read and write of spin states in organic diradicals." arXiv preprint arXiv:2406.03365(2024). Under Review.