Abstract
We utilize single-electron tunneling spectroscopy to measure the discrete energy levels in a nanometer-scale cobalt particle at mK, and find effective single-electron spin factors . These large factors do not result from the typical orbital contribution to factors, since the orbital angular momentum is quenched. Instead, they are due to nontrivial many-body excitations. A kink in the plot of conductance vs voltage and magnetic field is a signature of degenerate total spin on the particle. Spin-orbit interactions cause the new particle eigenstates to have “spin” that is an admixture of pure spin states. Fluctuations in the discrete energy level spacing allow for the total change in “spin” on the particle during a single-electron tunneling event to be , leading to a factor of around 6.
- Received 28 May 2013
DOI:https://doi.org/10.1103/PhysRevB.88.075303
©2013 American Physical Society