Special Seminar: Tailoring spin-spin interactions for emergent spin-spin properties

Quantum Information and sensing are scientific topics of active interest from an industrial and academic point of view(1, 2). The field’s relative nascency provides an excellent platform to explore a plethora of solutions to improve encoding and read-out of information which are arbitrary spin states generated via electric or magnetic fields resonant with spin→spin transitions. In this talk I will explore 2 different approaches, close to publication, that I have been working on, in the Richard H. Friend group at Cambridge: (a) To use a proxy to spin-orbit coupling by harnessing chirality which is a orthogonal dimension of physical manipulation and (b) by attaching 2 open shell semiconductors in various geometries to provide a manifold for competition between dipolar and exchange interactions. In method (a) I show how the information is transmitted and stored using the angular momentum quantum number which couples with out-coupled photons and in method (b) I show how the enhancement in excited state exchange interaction by orders of magnitude allows us to generate arbitrary correlated spin states using relatively small magnetic fields and also allows us to use photons to encode spin information for 200x longer than optical lifetimes at room temperature, enabling ground state spin polarisation for qubit applications like NV- centers(3). This has thus far only been shown for much shorter lifetimes and in the excited state(4, 5). All the materials I will talk about are purely organic and we have shown recently our prowess in accessing the synthetic chemical space of all of these materials(6).