Prof Vlatko Vedral FInstP

Abstract:

Whether many-body objects like organic molecules can exhibit full quantum behaviour, including entanglement, is an open fundamental question. We present a generic theoretical protocol for entangling two organic molecules, such as dibenzoterrylene in anthracene. The availability of organic dye molecules with two-level energy structures characterised by sharp and intense emission lines are characteristics that position them favourably as candidates for quantum information processing technologies involving single-photons. Quantum entanglement can in principle be generated between several organic molecules by carefully interfering their photoluminescence spectra. Major milestones have been achieved in the last 10 years showcasing entanglement in diverse systems including ions, cold atoms, superconductors, photons, quantum dots and NV-centres in diamond, but not yet in molecules.

Abstract:

The Pauli exclusion principle (PEP) has a tremendous impact on the properties and the behavior of most fermionic quantum systems. Remarkably, even stronger restrictions on fermionic natural occupation numbers follow from the fermionic exchange statistics. Based on a hierarchy induced by PEP we develop an operationally meaningful measure which allows to quantify the potential physical relevance of those generalized Pauli constraints (GPC) beyond the well-established relevance of PEP. By studying a few fermions in a harmonic trap we explore and confirm for the first time such nontrivial significance of GPC not only for weak couplings but even up to medium interaction strengths.