J. L. Luo

Publication List Details

Period

1998 - 2009

Number

80

Co-Authors

Electromagnetic response of LaO_0.94F_0.06FeAs: AC susceptibility and microwave surface resistance (2009)

Gallitto, A. Agliolo, Bonsignore, G., Bonura, M., Vigni, M. Li, Luo, J. L., Shevchun, A. F.

We discuss on the electromagnetic response of a polycrystalline sample of LaO_0.94F_0.06FeAs exposed to DC magnetic fields up to 10 kOe. The low- and high-frequency responses have been investigated...

Observation of Dirac Cone Electronic Dispersion in BaFe2As2 (2009)

Richard, P., Nakayama, K., Sato, T., Neupane, M., Bowen, J. H., ...

We performed an angle-resolved photoemission spectroscopy study of BaFe2As2, which is the parent compound of the so-called 122 phase of the iron-pnictide high-temperature superconductors. We reveal...

Superconducting state in the non-centrosymmetric Mg_{9.3}Ir_{19}B_{16.7} and Mg_{10.5}Ir_{19}B_{17.1} revealed by NMR (2009)

Tahara, K., Li, Z., Yang, H. X., Luo, J. L., Kawasaki, S., Zheng, Guo-qing

We report ^{11}B NMR measurements in non-centrosymmetric superconductors Mg_{9.3}Ir_{19}B_{16.7} (T_c=5.8 K) and Mg_{10.5}Ir_{19}B_{17.1} (T_c=4.8 K). The spin lattice relaxation rate and the Knight...

Angle-Resolved Photoemission Spectroscopy of Iron-Chalcogenide Superconductor Fe1.03Te0.7Se0.3 : Strong-Coupling Superconductivity and Universality of Inter-Band Scattering (2009)

Nakayama, K., Sato, T., Richard, P., Kawahara, T., Sekiba, Y., Qian, T., ...

We have performed high-resolution angle-resolved photoemission spectroscopy of iron-chalcogenide superconductor Fe1.03Te0.7Se0.3 (Tc = 13 K) to investigate the electronic structure relevant to...

Optical study on the spin-density wave properties in single crystalline Na$_{1-\delta}$FeAs (2009)

Hu, W. Z., Li, G., Zheng, P., Chen, G. F., Luo, J. L., Wang, N. L.

We report an optical investigation on the in-plane charge dynamics for Na$_{1-\delta}$FeAs single crystal. A clear optical evidence for the spin-density wave (SDW) gap is observed. As the...

Fermi surface topology and low-lying quasiparticle dynamics of parent Fe$_{1+x}$Te/Se Superconductor by orbital-polarization resolved ARPES (2009)

Xia, Y., Qian, D., Wray, L., Hsieh, D., Chen, G. F., Luo, J. L., ...

We report the first photoemission study of Fe$_{1+x}$Te - the host compound of the newly discovered iron-chalcogenide superconductors (maximum T$_c$ $\sim$ 27K). Our results reveal a pair of nearly...

Homogeneous vs. inhomogeneous coexistence of magnetic order and superconductivity probed by NMR in Co and K doped iron pnictides (2009)

Mayaffre, H., Horvatic, M., Berthier, C., Zhang, X. D., Wu, W., ...

In Ba(Fe0.95Co0.05)2As2 all of the 75As NMR intensity at the paramagnetic resonance position vanishes abruptly below Tonset(SDW)=56 K, indicating that magnetic (spin density wave) order is present in...

Origin of the structural phase transition at 130 K in BaNi$_2$As$_2$: a combined study of optical spectroscopy and band structure calculations (2009)

Chen, Z. G., Xu, G., Hu, W. Z., Zhang, X. D., Zheng, P., Chen, G. F., ...

BaNi$_2$As$_2$ exhibits a first order structural transition at 130 K. Understanding this structural transition is a crucial step towards understanding the electronic properties of the material. We...

Nonequilibrium quasiparticle dynamics in single crystals of Ba$_{0.6}$K$_{0.4}$Fe$_2$As$_2$ (2009)

Torchinsky, Darius H, Chen, G. F., Luo, J. L., Wang, N. L., Gedik, Nuh

We report on the quasiparticle dynamics in Ba$_{0.6}$K$_{0.4}$Fe$_2$As$_2$ ($T_c = 37 K$) as a function of temperature and excitation density. Quasiparticles are injected into single crystal samples...

Possible high temperature superconductivity in Ti-doped A-Sc-Fe-As-O (A= Ca, Sr) system (2009)

Chen, G. F., Yang, H. X., Li, J. Q., Zheng, P., Luo, J. L., ...

We report a systematic study on the effect of partial substitution of Sc$^{3+}$ by Ti$^{4+}$ in Sr$_{2}$ScFeAsO$_{3}$, Ca$_{2}$ScFeAsO$_{3}$ and Sr$_{3}$Sc$_{2}$Fe$_{2}$As$_{2}$O$_{5}$ on their...

Electronic Structure of the BaFe$_2$As$_2$ Family of Iron Pnictides (2009)

Yi, M., Lu, D. H., Analytis, J. G., ...

We use high resolution angle-resolved photoemission spectroscopy to study the band structure and Fermi surface topology of the BaFe$_2$As$_2$ iron pnictides. We observe two electron bands and two...

Multiple phase transitions in single-crystalline Na$_{1-\delta}$FeAs (2009)

Chen, G. F., Hu, W. Z., Luo, J. L., Wang, N. L.

Specific heat, resistivity, susceptibility, Hall coefficient and optical measurements were performed on the high quality single crystalline Na$_{1-\delta}$FeAs. This compound is found to undergo...

Fermi surface topology and low-lying quasiparticle structure of magnetically ordered Fe1+xTe (2009)

Xia, Y., Qian, D., Wray, L., Hsieh, D., Chen, G. F., Luo, J. L., ...

We report the first photoemission study of Fe1+xTe - the host compound of the newly discovered iron-chalcogenide superconductors. Our results reveal a pair of nearly electron- hole compensated Fermi...

Momentum-dependence of Superconducting Gap, strong-coupling dispersion Kink, and tightly bound Cooper pairs in the high-Tc (Sr,Ba)1-x(K,Na)xFe2As2 superconductors (2008)

Wray, L., Qian, D., Hsieh, D., Xia, Y., Li, L., Checkelsky, J. G., ...

We present a systematic angle-resolved photoemission spectroscopic study of the high-Tc superconductor class (Sr/Ba){1-x}(K/Na)xFe2As2. By utilizing a photon-energy-modulation contrast and scattering...

Experimental determination of the microscopic origin of magnetism in parent iron pnictides (2008)

Hsieh, D., Xia, Y., Wray, L., Qian, D., Gomes, K., Yazdani, A., ...

Like high Tc cuprates, the newly discovered iron based superconductors lie in close proximity to a magnetically ordered parent phase. However, while the magnetic order in parent cuprates is known to...

Superconducting gap symmetry of Ba0.6K0.4Fe2As2 studied by angle-resolved photoemission spectroscopy (2008)

Nakayama, K., Sato, T., Richard, P., Sekiba, Y., Souma, S., ...

We have performed high-resolution angle-resolved photoemission spectroscopy on the optimally-doped Ba$_{0.6}$K$_{0.4}$Fe$_2$As$_2$ compound and determined the accurate momentum dependence of the...

Electronic structure of optimally doped pnictide Ba$_{0.6}$K$_{0.4}$Fe$_2$As$_2$: a comprehensive ARPES investigation (2008)

Ding, H., Nakayama, K., Richard, P., Souma, S., Sato, T., Takahashi, T., ...

We have conducted a comprehensive angle-resolved photoemission study on the normal state electronic structure of the Fe-based superconductor Ba$_{0.6}$K$_{0.4}$Fe$_2$As$_2$. We have identified four...

Large quasiparticle thermal Hall conductivity in the superconductor $\rm Ba_{1-x}K_xFe_2As_2$ (2008)

Checkelsky, J. G., Li, Lu, Chen, G. F., Luo, J. L., Wang, N. L., Ong, N. P.

Both the thermal conductivity $\kappa_{xx}$ and thermal Hall conductivity $\kappa_{xy}$ in $\rm Ba_{1-x}K_xFe_2As_2$ display large peak anomalies in the superconducting state. The anomalies imply...

Raman phonons of $\alpha$-FeTe and Fe$_{1.03}$Se$_{0.3}$Te$_{0.7}$ single crystals (2008)

Xia, Tian-Long, Hou, D., Zhao, S. C., Zhang, A. M., Chen, G. F., Luo, J. L., ...

Polarized Raman scattering spectra of nonsuperconducting $\alpha$-FeTe and newly discovered superconducting Fe$_{1.03}$Se$_{0.3}$Te$_{0.7}$ single crystals are measured at room temperature. Phonon...

Electronic properties of single-crystalline Fe$_{1.05}$Te and Fe$_{1.03}$Se$_{0.30}$Te$_{0.70}$ (2008)

Chen, G. F., Chen, Z. G., Dong, J., Hu, W. Z., Li, G., Zhang, X. D., ...

We report on a comprehensive study of the transport, specific heat, magnetic susceptibility and optical spectroscopy on single crystal of Fe$_{1.05}$Te. We confirm that Fe$_{1.05}$Te undergoes a...

Band Structure and Fermi Surface of an Extremely Overdoped Iron-Based Superconductor KFe2As2 (2008)

Sato, T., Nakayama, K., Sekiba, Y., Richard, P., Souma, S., ...

We have performed high-resolution angle-resolved photoemission spectroscopy on heavily overdoped KFe_2As_2 (transition temperature (Tc = 3 K). We observed several renormalized bands near the Fermi...

Two superconducting gaps in LaFeAsO0.92F0.08 revealed by 75As nuclear quadrupole resonance (2008)

Kawasaki, S., Shimada, K., Chen, G. F., Luo, J. L., Wang, N. L., Zheng, Guo-qing

We report $^{75}$As nuclear quadrupole resonance (NQR) studies on superconducting oxypnictide LaFeAsO$_{0.92}$F$_{0.08}$ ($T_{\rm c}$ = 23 K). The temperature dependence of the spin lattice...

Doping evoluton of antiferromagnetic order and structural distortion in LaFeAsO$_{1-x}$F$_x$ (2008)

Huang, Q., Zhao, Jun, Lynn, J. W., Chen, G. F., Luo, J. L., Wang, N. L., ...

We use neutron scattering to study the structural distortion and antiferromagnetic (AFM) order in LaFeAsO$_{1-x}$F$_{x}$ as the system is doped with fluorine (F) to induce superconductivity. In the...

Competing energy scales in iron-based layered (Ba,K)Fe2As2 superconductors (2008)

Chia, Elbert E. M., Talbayev, D., Yuan, H. Q., Park, T., Thompson, J. D., ...

Recent discovery of superconductivity in Fe-based compounds, the only class of non-cuprate materials with superconducting transition temperatures (Tc) larger than 40 K, has generated tremendous...

Low energy spin waves and magnetic interactions in SrFe$_2$As$_2$ (2008)

Zhao, Jun, Yao, Dao-Xin, Li, Shiliang, Hong, Tao, Chen, Y., Chang, S., ...

We report inelastic neutron scattering studies of magnetic excitations in antiferromagnetically ordered SrFe$_{2}$As$_{2}$ ($T_{N}=220$ K), the parent compound of the FeAs-based superconductors. At...

Tightly-bound Cooper pair, quasiparticle kinks and clues on the pairing potential in a high Tc FeAs Superconductor (2008)

Wray, L., Qian, D., Hsieh, D., Xia, Y., Li, L., Checkelsky, J. G., ...

We present a systematic photoemission study of the newly discovered high Tc superconductor class (Sr/Ba)1-xKxFe2As2. By utilizing a unique photon energy range and scattering geometry we resolve the...

Observation of an Orbital Selective Electron-Mode Coupling in Fe-Based High-$T_c$ Superconductors (2008)

Richard, P., Sato, T., Nakayama, K., Souma, S., Takahashi, T., ...

We have performed an angle-resolved photoemission spectroscopy study of the new superconductor Ba$_{0.6}$K$_{0.4}$Fe$_2$As$_2$ in the low energy range. We report the observation of an anomaly around...

Superconductivity coexisting with phase-separated static magnetic order in (Ba,K)Fe$_{2}$As$_{2}$, (Sr,Na)Fe$_{2}$As$_{2}$ and CaFe$_{2}$As$_{2}$ (2008)

Goko, T., Aczel, A. A., Baggio-Saitovitch, E., Bud'ko, S. L., Canfield, P. C., Carlo, J. P., ...

The recent discovery and subsequent developments of FeAs-based superconductors have presented novel challenges and opportunities in the quest for superconducting mechanisms in correlated-electron...

Nearly Isotropic superconductivity in (Ba,K)Fe2As2 (2008)

Yuan, H. Q., Singleton, J., Balakirev, F. F., Baily, S. A., Chen, G. F., Luo, J. L., ...

Superconductivity was recently observed in the iron-arsenic-based compounds with a superconducting transition temperature (Tc) as high as 56K [1-7], naturally raising comparisons with the high Tc...

Muon spin relaxation studies of magnetic order and superfluid density in antiferromagnetic NdOFeAs, BaFe2As2 and superconducting (Ba,K)Fe2As2 (2008)

Aczel, A. A., Baggio-Saitovitch, E., Budko, S. L., Canfield, P. C., Carlo, J. P., Chen, G. F., ...

Zero-field (ZF) muon spin relaxation ($\mu$SR) measurements have revealed static commensurate magnetic order of Fe moments in NdOFeAs below $T_{N} \sim 135$ K, with the ordered moment size nearly...

Spin and Lattice Structure of Single Crystal SrFe2As2 (2008)

Zhao, Jun, Ratcliff II, W., Lynn, J. W., Chen, G. F., Luo, J. L., Wang, N. L., ...

We use neutron scattering to study the spin and lattice structure on single crystals of SrFe2As2, the parent compound of the FeAs based superconductor (Sr,K)Fe2As2. We find that SrFe2As2 exhibits an...

Probing superconducting energy gap from infrared spectroscopy on a Ba$_{0.6}$K$_{0.4}$Fe$_2$As$_2$ single crystal with T$_c$=37 K (2008)

Li, G., Hu, W. Z., Dong, J., Li, Z., Zheng, P., Chen, G. F., ...

We performed optical spectroscopy measurement on a superconducting Ba$_{0.6}$K$_{0.4}$Fe$_2$As$_2$ single crystal with T$_c$=37 K. Formation of the superconducting energy gaps in the far-infared...

Magnetic Order of the Iron Spins in NdOFeAs (2008)

Chen, Ying, Lynn, J. W., Li, J., Li, G., Chen, G. F., Luo, J. L., ...

Polarized and unpolarized neutron diffraction measurements have been carried out to investigate the iron magnetic order in undoped NdOFeAs. Antiferromagnetic order is observed below 141(6) K, which...

Multiple Nodeless Superconducting Gaps in (Ba0.6K0.4)Fe2As2 Superconductor from Angle-Resolved Photoemission Spectroscopy (2008)

Zhao, Lin, Liu, Haiyun, Zhang, Wentao, Meng, Jianqiao, Jia, Xiaowen, Liu, Guodong, ...

High resolution angle-resolved photoemission measurements have been carried out to study the superconducting gap in the (Ba0.6K0.4)Fe2As2 superconductor with Tc=35 K. Two hole-like Fermi surface...

Observation of Fermi-surface-dependent nodeless superconducting gaps in Ba0.6K0.4Fe2As2 (2008)

Ding, H., Richard, P., Nakayama, K., Sugawara, T., Arakane, T., Sekiba, Y., ...

The recent discovery of superconductivity in iron-arsenic compounds below a transition temperature (Tc) as high as 55K ended the monopoly of copper oxides (cuprates) in the family of high-Tc...

Fermi Surface and Band Renormalization in (Sr,K)Fe$_2$As$_2$ Superconductor from Angle-Resolved Photoemission Spectroscopy (2008)

Liu, Haiyun, Zhang, Wentao, Zhao, Lin, Jia, Xiaowen, Meng, Jianqiao, Liu, Guodong, ...

High resolution angle-resolved photoemission measurements have been carried out on (Sr,K)Fe$_2$As$_2$ superconductor (Tc=21 K). Three hole-like Fermi surface sheets are clearly resolved for the first...

Scanning tunneling microscopy of the 32 K superconductor (Sr1-xKx)Fe2As2 (2008)

Boyer, M. C., Chatterjee, Kamalesh, Wise, W. D., Chen, G. F., Luo, J. L., Wang, N. L., ...

The discovery of high temperature superconductivity in La[O1-xFx]FeAs at the beginning of this year [1] has generated much excitement and has led to the rapid discovery of similar compounds with as...

Structural and magnetic phase diagram of CeFeAsO1-xFx and its relationship to high-temperature superconductivity (2008)

Zhao, Jun, Huang, Q., De La Cruz, Clarina, Li, Shiliang, Lynn, J. W., Chen, Y., ...

We use neutron scattering to study the structural and magnetic phase transitions in the iron pnictides CeFeAsO1-xFx as the system is tuned from a semimetal to a high-transition-temperature (high-Tc)...

Transport and anisotropy in single-crystalline SrFe$_2$As$_2$ and $A_{0.6}$K$_{0.4}$Fe$_2$As$_2$ ($A$ = Sr, Ba) superconductors (2008)

Chen, G. F., Li, Z., Dong, J., Li, G., Hu, W. Z., Zhang, X. D., ...

We have successfully grown high quality single crystals of SrFe$_2$As$_2$ and A$_{0.6}$K$_{0.4}$Fe$_2$As$_2$(A=Sr, Ba) using flux method. The resistivity, specific heat and Hall coefficient have been...

Origin of the spin density wave instability in AFe$_2$As$_2$ (A=Ba, Sr) as revealed by optical spectroscopy (2008)

Hu, W. Z., Dong, J., Li, G., Li, Z., Zheng, P., Chen, G. F., ...

We performed optical spectroscopy measurement on single crystals of BaFe$_2$As$_2$ and SrFe$_2$As$_2$, the parent compounds of FeAs based superconductors. Both are found to be quite metallic with...

Superconductivity in hole-doped (Sr$_{1-x}$K$_x$)Fe$_2$As$_2$ (2008)

Chen, G. F., Li, Z., Li, G., Hu, W. Z., Dong, J., Zhang, X. D., ...

A series of layered (Sr$_{1-x}$K$_x$)Fe$_2$As$_2$ compounds with nominal x=0 to 0.40 are synthesized by solid state reaction method. Similar to other parent compounds of iron-based pnictide...

Raman spectra in iron-based quaternary CeO$_{1-x}$F$_x$FeAs and LaO$_{1-x}$F$_x$FeAs (2008)

Zhao, S. C., Hou, D., Wu, Y., Xia, T. L., Zhang, A. M., Chen, G. F., ...

Raman spectra have been measured on iron-based quaternary CeO$_{1-x}$F$_x$FeAs and LaO$_{1-x}$F$_x$FeAs with varying fluorine doping at room temperatures. A group analysis has been made to clarify...

Common Features in Electronic Structure of the Fe-Based Layered Superconductors from Photoemission Spectroscopy (2008)

Jia, Xiaowen, Liu, Haiyun, Zhang, Wentao, Zhao, Lin, Meng, Jianqiao, Liu, Guodong, ...

High resolution photoemission measurements have been carried out on non-superconducting LaOFeAs parent compound and various superconducting R(O1-xFx)FeAs (R=La, Ce and Pr) compounds. We found that...

MuSR studies of RE(O,F)FeAs (RE = La, Nd, Ce) and LaOFeP systems: possible incommensurate/stripe magnetism and superfluid density (2008)

Carlo, J. P., Uemura, Y. J., Goko, T., MacDougall, G. J., Rodriguez, J. A., Yu, W., ...

Muon spin relaxation (MuSR) measurements in iron oxy-pnictide systems have revealed: (1) commensurate long-range order in undoped LaOFeAs; (2) Bessel function line shape in La(O0.97F0.03)FeAs which...

Nernst effect of the new iron-based superconductor LaO$_{1-x}$F$_{x}$FeAs (2008)

Zhu, Z. W., Xu, Z. A., Lin, X., Cao, G. H., Feng, C. M., Chen, G. F., ...

We report the first Nernst effect measurement on the new iron-based superconductor LaO$_{1-x}$F$_{x}$FeAs $(x=0.1)$. In the normal state, the Nernst signal is negative and very small. Below $T_{c}$ a...

Magnetic Order versus superconductivity in the Iron-based layered La(O1-xFx)FeAs systems (2008)

De La Cruz, Clarina, Huang, Q., Lynn, J. W., Li, Jiying, Ratcliff II, W., Zarestky, J. L., ...

In high-transition temperature (high-Tc) copper oxides, it is generally believed that antiferromagnetism plays a fundamental role in the superconducting mechanism because superconductivity occurs...

Element substitution effect in transition metal oxypnictide Re(O$_{1-x}$F$_x$)TAs (Re=rare earth, T=transition metal) (2008)

Chen, G. F., Li, Z., Wu, D., Dong, J., Li, G., Hu, W. Z., ...

Different element substitution effects in transition metal oxypnictide Re(O$_{1-x}$F$_x$)TAs with Re=La, Ce, Nd, Eu, Gd, Tm, T=Fe, Ni, Ru, were studied. Similar to the La- or Ce-based systems, we...

Superconductivity at 41 K and its competition with spin-density-wave instability in layered CeO$_{1-x}$F$_x$FeAs (2008)

Chen, G. F., Li, Z., Wu, D., Li, G., Hu, W. Z., Dong, J., ...

A series of layered CeO$_{1-x}$F$_x$FeAs compounds with x=0 to 0.20 are synthesized by solid state reaction method. Similar to the LaOFeAs, the pure CeOFeAs shows a strong resistivity anomaly near...

Competing Orders and Spin-Density-Wave Instability in La(O$_{1-x}$F$_x$)FeAs (2008)

Dong, J., Zhang, H. J., Xu, G., Li, Z., Li, G., Hu, W. Z., ...

The interplay between different ordered phases, such as superconducting, charge or spin ordered phases, is of central interest in condensed matter physics. The very recent discovery of...

Strong-coupling superconductivity in layered nickel-based LaO$_{1-x}$F$_x$NiAs (2008)

Li, Z., Chen, G. F., Dong, J., Li, G., Hu, W. Z., Wu, D., ...

A series of layered nickel-based LaO$_{1-x}$F$_x$NiAs compounds with x=0 to 0.15 are synthesized by solid state reactions. The pure LaONiAs exhibits bulk superconductivity with Tc $\sim$ 2.75 K....

Superconducting properties of Fe-based layered superconductor LaO$_{0.9}$F$_{0.1-\delta}$FeAs (2008)

Chen, G. F., Li, Z., Li, G., Zhou, J., Wu, D., Dong, J., ...

We have employed a new route to synthesize single phase F-doped LaOFeAs compound and confirmed the superconductivity above 20 K in this Fe-based system. We show that the new superconductor has a...

Phonon softening and "forbidden" mode observed by Raman scattering in Na0.5CoO2 (2008)

Zhang, Q. M., An, M., Yuan, S. K., Wu, Y., Wu, D., Luo, J. L., ...

Polarized Raman scattering measurements have been performed on Na0.5CoO2 single crystal from 8 to 305 K. Both the A1g and E1g phonon modes show a softening below Tc1 ~ 83 K. Additionally, the A1g...

Band-dependent normal-state coherence in Sr$_{2}$RuO$_{4}$: Evidence from Nernst effect and thermopower measurements (2008)

Xu, X. F., Xu, Z. A., Liu, T. J., Fobes, D., Mao, Z. Q., Luo, J. L., ...

We present the first measurement on Nernst effect in the normal state of odd-parity, spin-triplet superconductor Sr$_{2}$RuO$_{4}$. Below 100 K, the Nernst signal was found to be negative, large,...

Low Energy Spin Waves and Magnetic Interactions in SrFe2As2 (2008)

Zhao, J., Yao, D. X., Li, S. L., Hong, T., Chen, Y., Chang, S., ...

We report inelastic neutron scattering studies of magnetic excitations in antiferromagnetically ordered SrFe2As2 (TN=200â"220 K), the parent compound of the FeAs-based superconductors. At low...

Giant Anisotropy of Magnetoresistance and "Spin Valve" effect in Antiferromagnetic $Nd_{2-x}Ce_xCuO_{4}$ (2007)

Wu, T., Wang, C. H., Wu, G., Fang, D. F., Luo, J. L., Liu, G T., ...

We have studied anisotropic magnetoresistance (MR) and magnetization with rotating magnetic field (B) within $CuO_2$ plane in lightly doped AF $Nd_{2-x}Ce_xCuO_{4}$. \emph{A giant anisotropy} in MR...

Complete d-Band Dispersion and the Mobile Fermion Scale in NaxCoO2 (2006)

Qian, D., Wray, L., Hsieh, D., Viciu, L., Cava, R. J., Luo, J. L., ...

We utilize fine-tuned polarization selection coupled with excitation-energy variation of photoelectron signal to image the \textit{complete d}-band dispersion relation in sodium cobaltates. A...

Optical study of MgTi$_2$O$_4$: Evidence for an orbital-Peierls state (2006)

Zhou, J., Li, G., Luo, J. L., Ma, Y. C., Wu, Dan, Zhu, B. P., ...

Dimension reduction due to the orbital ordering has recently been proposed to explain the exotic charge, magnetic and structural transitions in some three-dimensional (3D) transitional metal oxides....

Anisotropic Magnetoresistance in Charge-Ordering $Na_{0.34}(H_3O)_{0.15}CoO_2$:Strong Spin-Charge Coupling and Spin Ordering (2006)

Wang, C. H., Chen, X. H., Wu, G., Wu, T., Zhang, H. T., Luo, J. L., ...

Angular-dependent in-plane magnetoresistance (AMR) for single crystal $Na_{0.34}(H_3O)_{0.15}CoO_2$ with charge ordering is studied systematically. The anisotropic magnetoresistance shows a twofold...

Low-lying quasiparticle states and hidden collective charge instabilities in parent cobaltate superconductors (NaxCoO2) (2006)

Qian, D., Hsieh, D., Wray, L., Fedorov, A., Wu, D., Luo, J. L., ...

We report a state-of-the-art photoemission (ARPES) study of high quality single crystals of the NaxCoO2 series focusing on the fine details of the low-energy states. The Fermi velocity is found to be...

Evidence of s-wave pairing symmetry in layered superconductor Li$_{0.68}$NbO$_2$ from the specific heat measurement (2006)

Liu, G. T., Luo, J. L., Li, Z., Guo, Y. Q., Wang, N. L., Jin, D., ...

A high quality superconducting Li$_{0.68}$NbO$_2$ polycrystalline sample was synthesized by deintercalation of Li ions from Li$_{0.93}$NbO$_2$. The field dependent resistivity and specific heat were...

In-plane ferromagnetism in charge-ordering $Na_{0.55}CoO_2$ (2005)

Wang, C. H., Chen, X. H., Wu, T., Luo, X. G., Wang, G. Y., Luo, J. L.

The magnetic and transport properties are systematically studied on the single crystal $Na_{0.55}CoO_2$ with charge ordering and divergency in resistivity below 50 K. A long-range ferromagnetic...

In-plane substitution effect on the magnetic properties of two-dimensional Spin-gap system SrCu$_2$(BO$_3$)$_2$ (2005)

Liu, G. T., Luo, J. L., Guo, Y. Q., Su, S. K., Zheng, P., Wang, N. L., ...

A series of in-plane substituted compounds, including Cu-site (SrZn$_x$Cu$_{2-x}$(BO$_3$)$_2$), and B-site (SrCu$_2$(Si$_x$B$_{1-x}$O$_3$)$_2$) substitution, were synthesized by solid state reaction....

Optical properties of $MgCNi_3$ in the normal state (2005)

Zheng, P., Luo, J. L., Liu, G. T., Zhang, Y. L., Yu, R. C., Jin, C. Q., ...

We present the optical reflectance and conductivity spectra for non-oxide antiperovskite superconductor $MgCNi_{3}$ at different temperatures. The reflectance drops gradually over a large energy...

Angular-dependent Magnetoresistance Oscillations in Na$_{0.48}$CoO$_{2}$ Single Crystal (2005)

Hu, F., Liu, G. T., Luo, J. L., Wu, D., Wang, N. L., Xiang, T.

We report measurements of the c-axis angular-dependent magnetoresistance (AMR) for a Na$_{0.48}$CoO$_{2}$ single crystal, with a magnetic field of 10 T rotating within Co-O planes. Below the...

Physical properties, strontium ordering and structural modulation in layered hexagonal Sr0.35CoO2 (2005)

Yang, H. X., Shi, Y. G., Guo, Y. Q., Liu, X., Xiao, R. J., Luo, J. L., ...

Layered Sr0.35CoO2 has been synthesized by means of an ion exchange reaction from Na0.7CoO2. Resistivity measurements show that this material can be either metallic or semiconducting depending on the...

Electron-boson mode coupling and the pseudogap of Na$_x$CoO$_2$ by infrared spectroscopy (2005)

Wu, D., Luo, J. L., Wang, N. L.

We report the in-plane optical measurements on Na$_x$CoO$_2$ with 0.18$\leq$x$\leq$0.92. The crystal growth and characterization were described in detail. The spectral weight increases monotonically...

Hysteresis and Anisotropic Magnetoresistance in Antiferromagnetic $Nd_{2-x}Ce_xCuO_{4}$ (2004)

Chen, X. H., Wang, C. H., Wang, G. Y., Luo, X. G., Luo, J. L., Liu, G. T., ...

The out-of-plane resistivity ($\rho_c$) and magnetoresistivity (MR) are studied in antiferromangetic (AF) $Nd_{2-x}Ce_xCuO_{4}$ single crystals, which have three types of noncollinear...

Dimensional crossover and anomalous magnetoresistivity in single crystals $Na_xCoO_2$ (2004)

Wang, C. H., Chen, X. H., Luo, J. L., Liu, G. T., Lu, X. X., Zhang, H. T., ...

The in-plane ($\rho_{ab}$) and c-axis ($\rho_c$) resistivities, and the magnetoresistivity of single crystals $Na_xCoO_2$ with x = 0.7, 0.5 and 0.3 were studied systematically. $\rho_{ab}(T)$ shows...

Doping Effects on the two-dimensional Spin Dimer Compound $SrCu_2(BO_3)_2$ (2004)

Liu, G. T., Luo, J. L., Xiang, T., Wang, N. L., Wu, Z. H., Jing, X. N., ...

A series of compounds M$_{0.1}$Sr$_{0.9}$Cu$_2$(BO$_3$)$_2$ with Sr substituted by M=Al, La, Na and Y were prepared by solid state reaction. XRD analysis showed that these doping compounds are...

Metamagnetic Transition in Na$_{0.85}$CoO$_2$ Single Crystals (2004)

Luo, J. L., Wang, N. L., Liu, G. T., Wu, D., Jing, X. N., Hu, F., ...

We report the magnetization, specific heat and transport measurements of high quality Na$_{0.85}$CoO$_2$ single crystals in applied magnetic fields up to 14T. In high temperatures, the system is in a...

Optical properties of pyrochlore oxide $Pb_{2}Ru_{2}O_{7-{\delta}}$ (2003)

Zheng, P., Wang, N. L., Luo, J. L., Jin, R., Mandrus, D.

We present optical conductivity spectra for $Pb_{2}Ru_{2}O_{7-{\delta}}$ single crystal at different temperatures. Among reported pyrochlore ruthenates, this compound exhibits metallic behavior in a...

Strong electron-Boson coupling effect in the infrared spectra of $Tl_2 Ba_2 Ca Cu_2 O_{8+\delta}$ (2003)

Wang, N. L., Zheng, P., Luo, J. L., Chen, Z. J., Yan, S. L., Fang, L., ...

We report on a study of the in-plane infrared response of a \TBCCO film with $T_c$=108 K. The fingerprint evidence for a strong electron-Boson coupling has been observed. The raw reflectance below...

The magnetic field dependence of the electronic specific heat of Y_{0.8}Ca_{0.2}Ba_2Cu_3O_{6+x} (2001)

Luo, J. L., Loram, J. W., Xiang, T., Cooper, J. R., Tallon, J. L.

We have measured the electronic specific heat of $Y_{0.8}Ca_{0.2}Ba_2Cu_3O_{7-\delta}$ using a high-resolution differential technique from liquid helium temperature to room temperature in an applied...

Effect of Nitriding on the Anodic Behavior of Iron and Its Significance in Pitting Corrosion of Iron-Based Alloys. (1998)

Lu, Y. C., Luo, J. L., Ives, M. B.

The anodic behavior of both iron and nitrided iron has been studied in chloride-containing aqueous solutions at neutral and acidic pH values; the structure of the nitride has been characterized by...

Skeletal muscle glutathione after surgical trauma.

Luo, J L, Hammarqvist, F, Andersson, K, Wernerman, J

OBJECTIVE: The authors investigate the effect of surgical trauma on skeletal muscle concentrations of glutathione in patients undergoing selective abdominal surgery. SUMMARY BACKGROUND DATA: The...

Skeletal muscle glutathione after surgical trauma.

Luo, J L, Hammarqvist, F, Andersson, K, Wernerman, J

OBJECTIVE: The authors investigate the effect of surgical trauma on skeletal muscle concentrations of glutathione in patients undergoing selective abdominal surgery. SUMMARY BACKGROUND DATA: The...