5 research outputs found
Observation of giant circular dichroism induced by electronic chirality
Chiral phases of matter, characterized by a definite handedness, abound in
nature, ranging from the crystal structure of quartz to spiraling spin states
in helical magnets. In -TiSe a source of chirality has been proposed
that stands apart from these classical examples as it arises from combined
electronic charge and quantum orbital fluctuations. This may allow its
chirality to be accessed and manipulated without imposing either structural or
magnetic handedness. However, direct bulk evidence that broken inversion
symmetry and chirality are intrinsic to TiSe remains elusive. Here,
employing resonant elastic scattering of x-rays, we reveal the presence of
giant circular dichroism up to 40 at forbidden Bragg peaks that
emerge at the charge and orbital ordering transition. The dichroism varies
dramatically with incident energy and azimuthal angle. Comparison to calculated
scattering intensities unambiguously traces its origin to bulk chiral
electronic order in and establishes resonant elastic x-ray
scattering as a sensitive probe to electronic chirality.Comment: 6 pages, 4 figure
Charge redistribution, charge order and plasmon in LaSrCuO/LaCuO superlattices
Interfacial superconductors have the potential to revolutionize electronics,
quantum computing, and fundamental physics due to their enhanced
superconducting properties and ability to create new types of superconductors.
The emergence of superconductivity at the interface of
LaSrCuO/LaCuO (LSCO/LCO), with a T
enhancement of 10 K compared to the LaSrCuO bulk
single crystals, provides an exciting opportunity to study quantum phenomena in
reduced dimensions. To investigate the carrier distribution and excitations in
interfacial superconductors, we combine O K-edge resonant inelastic X-ray
scattering and atomic-resolved scanning transmission electron microscopy
measurements to study LaSrCuO/LaCuO
superlattices (x=0.15, 0.45) and bulk LaSrCuO films. We
find direct evidence of charge redistribution, charge order and plasmon in
LSCO/LCO superlattices. Notably, the observed behaviors of charge order and
plasmon deviate from the anticipated properties of individual constituents or
the average doping level of the superlattice. Instead, they conform
harmoniously to the effective doping, a critical parameter governed by the
T of interfacial superconductors.Comment: 8 pages, 5 figure
Coexistence of Multiple Stacking Charge Density Waves in Kagome Superconductor
The recently discovered kagome family (A =
K, Rb, Cs) exhibits rich physical phenomena, including non-trivial topological
electronic structure, giant anomalous Hall effect, charge density waves (CDW)
and superconductivity. Notably, CDW in is
evidenced to intertwine with its superconductivity and topology, but its nature
remains elusive. Here, we combine x-ray diffraction experiments and
density-functional theory calculations to investigate the CDWs in
and demonstrate the coexistence of 2
2 2 and 2 2 4 CDW stacking phases. Competition
between these CDW phases is revealed by tracking the temperature evolution of
CDW intensities, which also manifests in different transition temperatures
during warming- and cooling-measurements. We also identify a meta-stable
quenched state of after fast-cooling process.
Our study demonstrates the coexistence of competing CDW stackings in
, offering new insights in understanding the
novel properties of this system.Comment: 6 pages, 4 figure