0000000000448971
AUTHOR
Andrey Danilov
Spin-parity of the 13.35 MeV state and high-lying states around 20 MeV in excitation energy in 12C nucleus
A study of the 11B(3He,d)12C reaction at incident 3He energy Elab = 25 MeV has been performed at the K-130 cyclotron at the University of Jyväskylä, Finland. Differential cross sections have been measured for the 13.35 MeV state and for the states with excitation energy around 20 MeV in 12C. The data were analyzed with the DWBA method. A tentative assignment, 4−, is given for the state at 13.35 MeV in a joint study of the reaction and inelastic scattering of α-particles with the energy of 110 MeV. For the state at 20.98 MeV, the possible spin-parity 3− and the isospin T =0 are assigned for the first time. Our model description of the broad state at 21.6 MeV is consistent with the previous as…
Direct Identification of Dilute Surface Spins on Al2O3 : Origin of Flux Noise in Quantum Circuits
An on-chip electron spin resonance technique is applied to reveal the nature and origin of surface spins on Al2O3. We measure a spin density of 2.2×1017 spins/m2, attributed to physisorbed atomic hydrogen and S=1/2 electron spin states on the surface. This is direct evidence for the nature of spins responsible for flux noise in quantum circuits, which has been an issue of interest for several decades. Our findings open up a new approach to the identification and controlled reduction of paramagnetic sources of noise and decoherence in superconducting quantum devices.