arXiv subjects

M. Tinkham

Publications and source records attributed to M. Tinkham.

22 records · Page 2Linked to original sources

arXiv1997

Transition Temperature of Josephson Junction Arrays with Long-Range Interaction

We report measurements of the dependence on magnetic field and array size of the resistive transition of Josephson junction arrays with long-range interaction. Because every wire in these arrays has a large number of nearest-neighbors (9 or 18 in our case), a mean-field theory should provide an excellent description of this system. Our data agree well with this mean-field calculation, which predicts that Tc (the temperature below which the array exhibits macroscopic phase coherence) shows very strong commensurability effects and scales with array size.

cond-mat.supr-con↗

arXiv1997

Gate-Voltage Studies of Discrete Electronic States in Al Nanoparticles

We have investigated the spectrum of discrete electronic states in single, nm-scale Al particles incorporated into new tunneling transistors, complete with a gate electrode. The addition of the gate has allowed (a) measurements of the electronic spectra for different numbers of electrons in the same particle, (b) greatly improved resolution and qualitatively new results for spectra within superconducting particles, and (c) detailed studies of the gate-voltage dependence of the resonance level widths, which have directly demonstrated the effects of non-equilibrium excitations.

cond-mat.mes-hall↗

arXiv1996

Chaos, interactions, and nonequilibrium effects in the tunneling resonance spectra of small metallic particles

We explain the observation of clusters in the tunneling resonance spectra of small metallic particles of few nanometer size. Each cluster of resonances is identified with one excited single--electron state of the metal particle, shifted as a result of the different nonequilibrium occupancy configurations of the other single--electron states. Assuming the underlying classical dynamics of the electrons to be chaotic, we determine the typical shift to be $Δ/g$ where $g$ is the dimensionless conductance of the grain.

cond-mat↗

arXiv1996

Dynamic Scaling of Magnetic Flux Noise Near the KTB Transition in Overdamped Josephson Junction Arrays

We have used a dc Superconducting QUantum Interference Device to measure the magnetic flux noise generated by the equilibrium vortex density fluctuations associated with the Kosterlitz-Thouless-Berezinskii (KTB) transition in an overdamped Josephson junction array. At temperatures slightly above the KTB transition temperature, the noise is white for $f f_ξ$. Here $f_ξ\proptoξ^{-z}$, where $ξ$ is the correlation length and $z$ is the dynamic exponent. Moreover, when all frequencies are scaled by $f_ξ$, data for different temperatures and frequencies collapse on to a single curve. In addition, we have extracted the dynamic exponent $z$ and found $z=1.98\pm0.03$.

cond-mat↗