Investigating the Emergent Properties of Organized Spin Ensembles and Their Behavior at Interfaces

Quantum information science (QIS) remains an important field of research due to its far-reaching implications in computing, communication and advanced sensing applications. Molecular systems are the most recent candidates for QIS, with several recent perspectives and reviews discussing the valuable properties unique to such systems. Coordination compounds provide precise tailoring of specific magnetic properties through structural tuning, and phthalocyanines have been established as a versatile system. Vanadyl phthalocyanine (VOPc) is considered here, a spin ½ system with long (μs) coherence times. It is easily and predictably deposited on a range of substrates and so has been directly implemented in resonant cavities to promote spin-photon coupling, placed on functionalized surfaces, or incorporated into hybrid architectures for sensing applications.<br/><br/>Read-out of the stored quantum information is a key requirement of all spin qubits and much work is being done on molecular compounds to achieve optical readout. Here, we investigate the possibility of a digital state readout by combining a molecular spin system to a valleytronic material. Films consisting of a few layers of transition metal dichalcogenides (TMDC) have demonstrated circular polarized photoluminescence (PL) from the transition to a direct band gap semiconductor. Chiral emission is relevant to spin-selective optoelectronics and combining the molecular spin qubit with a TMDC substrate could lead to interesting opportunities in QIS. However, at this stage little is known of the electronic and spin interactions at such an interface and the extent of spin-valley cooperativity. We therefore present a comparative magneto-optical study of the VOPc thermally evaporated on MoS₂, MoSe₂ and WSe₂ as a function of polarization. This provides critical information to design new architectures for quantum devices.