1,959 research outputs found
Self-contained Kondo effect in single molecules
Kondo coupling of f and conduction electrons is a common feature of
f-electron intermetallics. Similar effects should occur in carbon ring
systems(metallocenes). Evidence for Kondo coupling in Ce(C8H8)2 (cerocene) and
the ytterbocene Cp*2Yb(bipy) is reported from magnetic susceptibility and
L_III-edge x-ray absorption spectroscopy. These well-defined systems provide a
new way to study the Kondo effect on the nanoscale, should generate insight
into the Anderson Lattice problem, and indicate the importance of this
often-ignored contribution to bonding in organometallics.Comment: 4 pages, 5 figures (eps
Theory of phase-locking in generalized hybrid Josephson junction arrays
A recently proposed scheme for the analytical treatment of the dynamics of
two-dimensional hybrid Josephson junction arrays is extended to a class of
generalized hybrid arrays with ''horizontal'' shunts involving a capacitive as
well as an inductive component. This class of arrays is of special interest,
because the internal cell coupling has been shown numerically to favor in-phase
synchronization for certain parameter values. As a result, we derive limits on
the circuit design parameters for realizing this state. In addition, we obtain
formulas for the flux-dependent frequency including flux-induced switching
processes between the in-phase and anti-phase oscillation regime. The treatment
covers unloaded arrays as well as arrays shunted via an external load.Comment: 24 pages, REVTeX, 5 Postscript figures, Subm. to Phys. Rev.
Effect of Spin–Orbit Coupling on Phonon-Mediated Magnetic Relaxation in a Series of Zero-Valent Vanadium, Niobium, and Tantalum Isocyanide Complexes.
Spin-vibronic coupling leads to spin relaxation in paramagnetic molecules, and an understanding of factors that contribute to this phenomenon is essential for designing next-generation spintronics technology, including single-molecule magnets and spin-based qubits, wherein long-lifetime magnetic ground states are desired. We report spectroscopic and magnetic characterization of the isoelectronic and isostructural series of homoleptic zerovalent transition metal triad M(CNDipp)6 (M = V, Nb, Ta; CNDipp = 2,6-diisopropylphenyl isocyanide) and show experimentally the significant increase in spin relaxation rate upon going from V to Nb to Ta. Correlated electronic calculations and first principle spin–phonon computations support the role of spin–orbit coupling in modulating spin–phonon relaxation. Our results provide experimental evidence that increasing magnetic anisotropy through spin–orbit coupling interactions leads to increased spin–vibronic relaxation, which is detrimental to long spin lifetime in paramagnetic molecules
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