Room-temperature coherence boosting of molecular graphenoids

 

The 3D molecular structure

Federico Lombardi, Ming-Yee Tsang and Professor Lapo Bogani formed a research team with The Institute for Nanospectroscopy in Berlin, the Centre for Advanced Electronics in Dresden and the Department of Chemistry at the University of Oxford.  Together they explored the usage of pulse sequence optimization to boost the quantum properties of topological defects in molecular graphenoids at high temperatures.

They reached spin-lattice relaxation times on the same order as those from the best quantum devices in literature, ~1 ms at room temperature.  The coherence time was heavily affected by the hyperfine interaction, and particularly by the high concentration of hydrogen atoms.

The team tested and compared the applicability and performance of different decoupling sequences in enhancing the coherence, identifying the best-performing sequences for the purposes of robust state initialization and coherence optimization.  Up to 30 us coherence times were reached.  In their paper 'Room-temperature coherence boosting of molecular graphenoids by environmental spectral decomposition' published in Physical Review B, the team provides insight into the system-environment interaction mechanisms, with a semi-classical model that considers the nuclear bath as a source of a classical random noise and the dynamical decoupling as a filter function.  The full deconvolution of the noise spectrum of the bath was obtained, and the paper shows how the noise density has a Lorentzian shape whose parameters describe the nuclear-bath dynamics.