Rotatable high-resolution ARPES system for tunable linear-polarization geometry.

A rotatable high-resolution angle-resolved photoemission spectroscopy (ARPES) system has been developed to utilize tunable linear-polarization geometries on the linear undulator beamline (BL-1) at Hiroshima Synchrotron Radiation Center. By rotating the whole ARPES measurement system, the photoelectron detection plane can be continuously changed from parallel to normal against the electric field vector of linearly polarized undulator radiation. This polarization tunability enables us to identify the symmetry of the initial electronic states with respect to the mirror planes, and to selectively observe the electronic states based on the dipole selection rule in the photoemission process. Specifications of the rotatable high-resolution ARPES system are described, as well as its capabilities with some representative experimental results.

Coherent heavy quasiparticles in a CePt5 surface alloy.

We report on the results of a high-resolution angle-resolved photoemission study on the ordered surface alloy CePt(5). The temperature dependence of the spectra show the formation of the coherent low-energy heavy-fermion band near the Fermi level. These experimental data are supported by a multiband model calculation in the framework of the dynamical mean-field theory.

Effect of topotecan as second-line chemotherapy for small cell lung cancer patients with interstitial lung disease.

Small cell lung cancer with interstitial lung disease (ILD-SCLC) is difficult to treat because of the risk of fatal pneumonitis. Our study aims to evaluate the validity of topotecan (TOP) as chemotherapy for patients with relapsed ILD-SCLC. Overall survival was compared between TOP and other drugs as second-line treatments for ILD-SCLC patients. Forty-seven patients began chemotherapy and second-line treatment was administered in 48.5% of relapsed cases. The response rate of TOP for second-line therapy was 16.7%. Hematologic toxicities were grade 4 anemia, grade 3 neutropenia and grade 3 thrombocytopenia. Mild pulmonary toxicity was observed in 1 case. Patients receiving TOP as second-line treatment showed no significant difference in survival when compared to patients who underwent other regimens (median survival time 179 vs. 76 days; p =0.76). TOP is a well tolerated drug and is a viable candidate for second-line treatment of ILD-SCLC patients.

Electronic structure of charge- and spin-controlled Sr(1-(x+y))La(x+y)Ti(1-x)Cr(x)O3.

We present the electronic structure of Sr(1-(x+y))La(x+y)Ti(1-x)Cr(x)O3 investigated by high-resolution photoemission spectroscopy. In the vicinity of the Fermi level, it was found that the electronic structure was composed of a Cr 3d local state with the t(2g)3 configuration and a Ti 3d itinerant state. The energy levels of these Cr and Ti 3d states are well interpreted by the difference of the charge-transfer energy of both ions. The spectral weight of the Cr 3d state is completely proportional to the spin concentration x irrespective of the carrier concentration y, indicating that the spin density can be controlled by x as desired. In contrast, the spectral weight of the Ti 3d state is not proportional to y, depending on the amount of Cr doping.

Kink in the dispersion of layered strontium ruthenates.

We present detailed energy dispersions near the Fermi level along the high symmetry line GammaX on the monolayer and bilayer strontium ruthenates Sr2RuO4 and Sr3Ru2O7, determined by high-resolution angle-resolved photoemission spectroscopy. A kink in the dispersion is clearly shown for the both ruthenates. The energy position of the kink and the slope in the low-energy part near the Fermi level are almost identical between them, whereas the dispersion in the high-energy part varies, like the behavior of the kink for the cuprate superconductors.

Rotation detection by optical heterodyne fiber gyro with frequency output.

A fiber gyro with optical heterodyne detection is proposed. The experimental setup has been constructed and tested. Both the frequency difference in the fiber and the path-length difference between counterpropagating waves are eliminated to reduce output drift. An electronic circuit for phase-nulling detection has been constructed, which gives an electronic frequency output in proportion to the rotation rate. Direct frequency modulation of a single-mode laser diode has been adopted to reduce the noise that is due to the backward Rayleigh scattering. A short time resolution of the rotation rate of about 5 deg/h for an integration time of 1 sec. (0.0014 deg/sec) has been achieved with good linearity, for an integration time of 1 sec.

Fiber-optic laser gyro with easily introduced phase-difference bias.

An optical system for easy introduction of phase-difference bias to optimize the sensitivity of the fiber-optic laser gyro is proposed. The theory of using a laser diode has been considered, and the rotation detection experiment has been performed. The experimental setup consists of a 300-m long single-mode optical fiber, individual optical components, and a laser diode stabilized by a thermal controller and an optical isolator. Short-time resolution of the rotation rate better than 0.87 mrad/sec has been achieved with good linearity.