5,922 research outputs found
-wave Pairing in BiS Superconductors
Recent angle resolved photoemission spectroscopy(ARPES) experiments have
suggested that BiS based superconductors are at very low electron doping.
Using random phase approximation(RPA) and functional renormalization group(FRG)
methods, we find that -wave pairing symmetry belonging to A
irreducible representation is dominant at electron doping . The pairing
symmetry is determined by inter-pocket nesting and orbital characters on the
Fermi surfaces and is robust in a two-orbital model including both Hund's
coupling , and Hubbard-like Coulomb interactions and with
relatively small (). With the increasing electron doping, the
g-wave state competes with both the s-wave and d-wave states
and no pairing symmetry emerges dominantly.Comment: published version, EPL(editor's choice
Quantum coherence of the molecular states and their corresponding currents in nanoscale Aharonov-Bohm interferometers
By considering a nanoscale Aharonov-Bohm (AB) interferometer containing a
parrallel-coupled double dot coupled to the source and drain electrodes, we
investigate the AB phase oscillations of transport current via the bonding and
antibonding state channels. The results we obtained justify the experimental
analysis given in [Phys. Rev. Lett. \textbf{106}, 076801 (2011)] that bonding
state currents in different energy configurations are almost the same. On the
other hand, we extend the analysis to the transient transport current
components flowing through different channels, to explore the effect of the
parity of bonding and antibonding states on the AB phase dependence of the
corresponding current components in the transient regime. The relations of the
AB phase dependence between the quantum states and the associated current
components are analyzed in details, which provides useful information for the
reconstruction of quantum states through the measurement of the transport
current in such systems. With the coherent properties in the quantum dot states
as well as in the transport currents, we also provide a way to manipulate the
bonding and antibonding states by the AB magnetic flux.Comment: 10 pages, 7 figure
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