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Reflections on (Palaeo) Climate/Global Changes: Past/Present/Future
Published in Moayad N. Khalaf, Michael Olegovich Smirnov, Porteen Kannan, A. K. Haghi, Environmental Technology and Engineering Techniques, 2020
Francisco Torrens, Gloria Castellano
A switchable interaction between pairs of highly coherent qubits is a crucial ingredient for the physical realization of quantum information processing. One promising route to enable quantum logic operations involves the use of nuclear spins as protected elementary units of information, qubits. Sessoli group proposed a simple way to use fast electronic spin excitations to switch the effective interaction between nuclear spin qubits and the realization of a two-qubit molecular architecture based on highly coherent vanadyl moieties to implement quantum logic operations.31 Controlled generation of entanglement between qubits is possible via chemically tuned magnetic coupling between electronic spins, which is clearly evidenced by the splitting of the VIV hyperfine lines in the continuous-wave electron paramagnetic resonance spectrum. The system was characterized by pulsed electron paramagnetic resonance (EPR) spectroscopy, evidencing remarkably long coherence times. The experimentally derived spin Hamiltonian parameters were used to simulate the system dynamics under the sequence of pulses required to implement quantum gates in a realistic description, which includes the harmful effect of decoherence, which shows the possibility of using the molecular complex to implement a controlled-Z (cZ) gate and simple quantum simulations. They proposed a proof-of-principle experiment based on the simulation of the quantum tunneling of the magnetization in an S = 1 spin system.
Forty years of the Staebler–Wronski effect
Published in Philosophical Magazine, 2018
Satish Chandra Agarwal, Shobit Omar
Time-domain pulsed spectroscopy (pulsed electron paramagnetic resonance EPR) is used to study the defects in a-Si:H, before and after light soaking [19]. The experiment looks at (i) the interaction between electron–electron spins (defect sites) and also (ii) between electron-nuclear spins (proton). The relaxation of electron spin echoes of these defects shows that the interaction of type (i) arising from the defects that are clustered on the surface, decay faster than the point defects of type (ii) inside the bulk. The number of the two types of defects is about the same in the annealed state. After light soaking, about 21% are of type (i). This shows that a considerable number of defects are on internal surfaces of microvoids, and that microvoids play an important role in the SWE [19].