2,876 research outputs found
Magneto-optics induced by the spin chirality in itinerant ferromagnet NdMoO
It is demonstrated both theoretically and experimentally that the spin
chirality associated with a noncoplanar spin configuration produces a
magneto-optical effect. Numerical study of the two-band Hubbard model on a
triangle cluster shows that the optical Hall conductivity
is proportional to the spin chirality. The detailed comparative experiments on
pyrochlore-type molybdates MoO with Nd (Ising-like moments)
and Gd (Heisenberg-like ones) clearly distinguishes the two mechanisms,
i.e., spin chirality and spin-orbit interactions. It is concluded that for
=Nd, is dominated by the spin chirality for the dc
() and the incoherent intraband optical transitions between
Mo atoms.Comment: 4 pages, 5 figures. submitted to Phys. Rev.
Comment on "Origin of Giant Optical Nonlinearity in Charge-Transfer--Mott Insulators: A New Paradigm for Nonlinear Optics"
Comment on Phys. Rev. Lett. 86, 2086 (2001)Comment: 1 page, 1 eps figur
Anomalous Hall Effect and Magnetic Monopoles in Momentum-Space
Efforts to find the magnetic monopole in real space have been made in cosmic
rays and in accelerators, but up to now there is no firm evidence for its
existence due to the very heavy mass GeV. However, we show that
the magnetic monopole can appear in the crystal-momentum space of solids in the
accessible low energy region (eV) in the context of the anomalous
Hall effect. We report experimental results together with first-principles
calculations on the ferromagnetic crystal SrRuO that provide evidence for
the magnetic monopole in the crystal-momentum space.Comment: 4 figures, the supporting-online-materails are include
Dimensionality dependence of optical nonlinearity and relaxation dynamics in cuprates
Femtosecond pump-probe measurements find pronounced dimensionality dependence
of the optical nonlinearity in cuprates. Although the coherent two-photon
absorption (TPA) and linear absorption bands nearly overlap in both quasi-one
and two-dimensional (1D and 2D) cuprates, the TPA coefficient is one order of
magnitude smaller in 2D than in 1D. Furthermore, picosecond recovery of optical
transparency is observed in 1D cuprates, while the recovery in 2D involves
relaxation channels with a time scales of tens of picoseconds. The experimental
results are interpreted within the two-band extended Hubbard model.Comment: 10 pages, 4 figure
Multimedia based E-learning tools for dynamic modeling of dc-dc converters
Author name used in this publication: C. K. TseRefereed conference paper2005-2006 > Academic research: refereed > Refereed conference paperVersion of RecordPublishe
Liver function changes after transarterial chemoembolization in US hepatocellular carcinoma patients: The LiverT study
Background: The real-world incidence of chronic liver damage after transarterial chemoembolization (TACE) is unclear. LiverT, a retrospective, observational study, assessed liver function deterioration after a single TACE in real-world hepatocellular carcinoma (HCC) patients in US practice. Methods: Eligible HCC patients identified from Optum's integrated database using standard codes as having had an index TACE between 2010 and 2016 with no additional oncologic therapy in the subsequent 3 months. At least one laboratory value (bilirubin, albumin, aspartate transaminase [AST], alanine transaminase [ALT], international normalized ratio [INR]) was required at baseline and the acute ( 6429 days after TACE) and chronic (30-90 days after TACE) periods. Due to lack of universally accepted liver function deterioration criteria, clinically meaningful changes in laboratory parameters were pre-defined by authors (FP, RM, and SO). Results: Of the 3963 TACE patients, 572 were eligible for analyses. Deterioration of liver function from baseline occurred in the acute period and persisted in the chronic period (bilirubin 30 and 23%, albumin 52 and 31%, AST 44 and 25%, ALT 43 and 25%, INR 25 and 15%, respectively). In a subgroup analysis, a higher proportion of patients with diabetes had deterioration in AST and ALT. Conclusions: A clinically meaningful proportion of real-world HCC patients had deterioration of liver function-related laboratory values 30-90 days after a single TACE in modern US practice. Future electronic health record research may help determine causality. The present findings highlight the need for the careful selection of patients for TACE, which is important to help optimize the benefit of the overall HCC treatment course
Relaxation Dynamics of Photocarriers in One-Dimensional Mott Insulators Coupled to Phonons
We examine recombination processes of photocarriers in one-dimensional Mott
insulators coupled to phonons. Performing density matrix renormalization group
calculations, we find that, even for small electron-phonon coupling, many
phonons are generated dynamically, which cause initial relaxation process after
the irradiation. At the same time, spin-charge coupling coming from mixing of
high- and low-energy states by the irradiation is suppressed. We discuss
differences between Mott and band insulators in terms of relaxation dynamics.Comment: 5 pages, 3 figure
Pump Built-in Hamiltonian Method for Pump-Probe Spectroscopy
We propose a new method of calculating nonlinear optical responses of
interacting electronic systems. In this method, the total Hamiltonian (system +
system-pump interaction) is transformed into a different form that (apparently)
does not have a system-pump interaction. The transformed Hamiltonian, which we
call the pump built-in Hamiltonian, has parameters that depend on the strength
of the pump beam. Using the pump built-in Hamiltonian, we can calculate
nonlinear responses (responses to probe beams as a function of the pump beam)
by applying the {\em linear} response theory. We demonstrate the basic idea of
this new method by applying it to a one-dimensional, two-band model, in the
case the pump excitation is virtual (coherent excitation). We find that the
exponent of the Fermi edge singularity varies with the pump intensity.Comment: 6 page
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