Light-driven molecular spin qubits

Quantum Information Science is set to revolutionize the way we live, work, and understand our world. At its core is the qubit, the fundamental unit of quantum information. Molecules can leverage their electron and nuclear spins to function as qubits, offering unique benefits such as atomic control of magnetic, optical, and electronic properties, and scalable production with high reproducibility. However, like other qubit technologies, they require sub-kelvin temperatures to generate significant differences in the Boltzmann spin populations, which is essential for qubit initialization. Additionally, spin information readout primarily relies on microwave detection, which poses challenges in sensitivity and integration with conventional semiconductor technology. These factors hamper the path to everyday quantum applications in terms of versatility, energy consumption, and practical implementation.In the LIGHT-QIS project, I envision two transformative leaps in molecular qubits that will establish them as a cornerstone for quantum applications. First, I will harness light-induced spin-selective processes to generate non-equilibrium initialization of molecular qubits at liquid nitrogen temperatures and above. The use of light will also unlock new possibilities, such as the control of magnetic interactions between qubits, enabling the creation of light-switchable quantum gates. Second, I will integrate optically initialized molecular qubits into thin films of organic semiconductors to fabricate devices, enabling spin-to-charge conversion through electrically detected magnetic resonance techniques. LIGHT-QIS will focus on lab-scale devices where ensembles of qubits can be simultaneously initialized, manipulated, and read out. Ultimately, LIGHT-QIS has the potential to make quantum technologies impactful in everyday life beyond niche applications that require low temperatures and resource-intensive fabrication methods.