17,360 research outputs found
Evidence of orbit-selective electronic kagome lattice with planar flat-band in correlated paramagnetic YCr6Ge6
Electronic properties of kagome lattice have drawn great attention recently.
In associate with flat-band induced by destructive interference and Dirac
cone-type dispersion, abundant exotic phenomena have been theoretically
discussed. The material realization of electronic kagome lattice is a crucial
step towards comprehending kagome physics and achieving novel quantum phases.
Here, combining angle-resolved photoemission spectroscopy, transport
measurements and first-principle calculations, we expose a planar flat-band in
paramagnetic YCr6Ge6 as a typical signature of electronic kagome lattice. We
unearth that the planar flat-band arises from the dz2 electrons with
intra-kagome-plane hopping forbidden by destructive interference. On the other
hand, the destructive interference and flatness of the dx2-y2 and dxy bands are
decomposed possibly due to additional in-plane hopping terms, but the Dirac
cone-type dispersion is reserved near chemical potential. We explicitly unveil
that orbital character plays an essential role to realize electronic kagome
lattice in bulk materials with transition metal kagome layers. Paramagnetic
YCr6Ge6 provides an opportunity to comprehend intrinsic properties of
electronic kagome lattice as well as its interplays with spin orbit coupling
and electronic correlation of Cr-3d electrons, and be free from complications
induced by strong local moment of ions in kagome planes.Comment: 19 pages, 4 figure
Vortex dynamics of a -wave superconductor
The vortex dynamics of a d+is-wave superconductor is studied numerically by
simulating the time-dependent Ginzburg-Landau equations. The critical fields,
the free flux flow, and the flux flow in the presence of twin-boundaries are
discussed. The relaxation rate of the order parameter turns out to play an
important role in the flux flow. We also address briefly the intrinsic Hall
effect in d- and d+is-wave superconductors.Comment: 5 pages, 5 figure
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