Whether a metallic ground state exists in a two-dimensional system beyond Anderson localization remains an unresolved question. We studied how quantum phase coherence evolves across superconductor–metal–insulator transitions through magnetoconductance quantum oscillations in nanopatterned high-temperature superconducting films. We tuned the degree of phase coherence by varying the etching time of our films. Between the superconducting and insulating regimes, we detected a robust intervening anomalous metallic state characterized by saturating resistance and oscillation amplitude at low temperatures. Our measurements suggest that the anomalous metallic state is bosonic and that the saturation of phase coherence plays a prominent role in its formation.

The development of devices suitable for heat management requires materials whose thermal properties and synthesis are well controlled.

Intercalation of metal ions into double-stranded DNA has recently been proposed as a path to efficient charge transport in DNA wires. Until now, the effect of Ag(I) intercalation between mismatched cytosine nucleobases on the conductance of DNA has not been assessed. Here we use a scanning tunneling microscopy (STM) break-junction technique to evaluate and compare the single molecule conductance of polynucleotide sequences of 11 base pairs in length. The resulting single molecule conductance for Ag(I)−polyC is found to be an order of magnitude greater than the control strand made using canonical Watson−Crick pairing. This finding suggests that Ag(I) intercalation alters the dominant electron transport process from standard π-orbital delocalization common in sequences with multiple stacked guanines to an alternate and ultimately more efficient conduit.