819 research outputs found
Comment on "Multiple Bosonic Mode Coupling in Electron Self-Energy of (LaSr)CuO"
We calculate the photoemission spectral response using the extracted
of Zhou et al (cond-mat/0405130) as an input and we find that the
reported Re has more strucure than physically possible. Therefore, the
"fine structure" most likely reflects the experimental noise.Comment: Comment on cond-mat/0405130, "energy resolution" improve
Electronic structure basis for the titanic magnetoresistance in WTe
The electronic structure basis of the extremely large magnetoresistance in
layered non-magnetic tungsten ditelluride has been investigated by
angle-resolved photoelectron spectroscopy. Hole and electron pockets of
approximately the same size were found at the Fermi level, suggesting that
carrier compensation should be considered the primary source of the effect. The
material exhibits a highly anisotropic, quasi one-dimensional Fermi surface
from which the pronounced anisotropy of the magnetoresistance follows. A change
in the Fermi surface with temperature was found and a high-density-of-states
band that may take over conduction at higher temperatures and cause the
observed turn-on behavior of the magnetoresistance in WTe was identified
Application of the scattering rate sum-rule to the interplane optical conductivity of high temperature superconductors: pseudogap and bi-layer effects
We use a recently proposed model of the interplane conductivity of high
temperature superconductors to investigate the `scattering rate sum-rule'
introduced by Basov and co-workers. We present a new derivation of the
sum-rule. The quantal and thermal fluctuations of the order parameter which
have been argued to produce the observed pseudogap behavior are shown to
increase the total integrated `scattering rate' but may either increase or
decrease the `quasiparticle' contribution from frequencies greater than twice
the superconducting gap.Comment: 4 pages, 5 figures, revise
Photoemission Spectroscopy of Magnetic and Non-magnetic Impurities on the Surface of the BiSe Topological Insulator
Dirac-like surface states on surfaces of topological insulators have a chiral
spin structure that suppresses back-scattering and protects the coherence of
these states in the presence of non-magnetic scatterers. In contrast, magnetic
scatterers should open the back- scattering channel via the spin-flip processes
and degrade the state's coherence. We present angle-resolved photoemission
spectroscopy studies of the electronic structure and the scattering rates upon
adsorption of various magnetic and non-magnetic impurities on the surface of
BiSe, a model topological insulator. We reveal a remarkable
insensitivity of the topological surface state to both non-magnetic and
magnetic impurities in the low impurity concentration regime. Scattering
channels open up with the emergence of hexagonal warping in the high-doping
regime, irrespective of the impurity's magnetic moment.Comment: 5 pages, 4 figure
The Ground State of the Pseudogap in Cuprate Superconductors
We present studies of the electronic structure of La2-xBaxCuO4, a system
where the superconductivity is strongly suppressed as static spin and charge
orders or "stripes" develop near the doping level of x=1/8. Using
angle-resolved photoemission and scanning tunneling microscopy, we detect an
energy gap at the Fermi surface with magnitude consistent with d-wave symmetry
and with linear density of states, vanishing only at four nodal points, even
when superconductivity disappears at x=1/8. Thus, the non-superconducting,
"striped" state at x=1/8 is consistent with a phase incoherent d-wave
superconductor whose Cooper pairs form spin/charge ordered structures instead
of becoming superconducting.Comment: This is the author's version of the wor
Quasiparticle Liquid in the Highly Overdoped Bi2212
We present results from the study of a highly overdoped (OD) Bi2212 with a
K using high resolution angle-resolved photoemission spectroscopy.
The temperature dependent spectra near the () point show the presence of
the sharp peak well above . From the nodal direction, we make comparison
of the self-energy with the optimally doped and underdoped cuprates, and the
Mo(110) surface state. We show that this OD cuprate appears to have properties
that approach that of the Mo. Further analysis shows that the OD has a more
-independent lineshape at the Fermi surface than the lower-doped cuprates.
This allows for a realistic comparison of the nodal lifetime values to the
experimental resistivity measurements via Boltzmann transport formulation. All
these observations point to the validity of the quasiparticle picture for the
OD even in the normal state within a certain energy and momentum range.Comment: 4 pages, 4 figure
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