High-temperature interface superconductivity between metallic and insulating cuprates (2008)
Gozar, A., Logvenov, G., Kourkoutis, L. Fitting, Bollinger, A. T., Giannuzzi, L. A., Muller, D. A., ...
High-temperature superconductivity confined to nanometer-size interfaces has been a long standing goal because of potential applications^{1,2} and the opportunity to study quantum phenomena in...
AC and DC Conductivity Anisotropies in Lightly Doped La(2-x)Sr(x)CuO(4) (2008)
Neto, M. B. Silva, Blumberg, G., Gozar, A., Komiya, Seiki, Ando, Yoichi
The AC and DC conductivity anisotropies in the low temperature orthorhombic phase of lightly doped La(2-x)Sr(x)CuO(4) are ascribed to the rotational symmetry broken, localized impurity states...
Smadici, S., Lee, J. C. T., Wang, S., Abbamonte, P., Gozar, A., Logvenov, G., ...
We have used resonant soft x-ray scattering to quantify the distribution of doped holes in a superlattice consisting of two layers of nominally insulating $\rm La_{2}CuO_{4}$ (LCO) layers and four...
Surface Structure Analysis of Atomically Smooth BaBiO$_3$ Films (2007)
Gozar, A., Logvenov, G., Butko, V. Y., Bozovic, I.
Using low energy Time-of-Flight Scattering and Recoil Spectroscopy (TOF-SARS) and Mass Spectroscopy of Recoiled Ions (MSRI) we analyze the surface structure of an atomically smooth BaBiO$_3$ film...
Benfatto, L., Neto, M. B. Silva, Gozar, A., Dennis, B. S., Blumberg, G., Miller, L. L., ...
We compare the theoretical predictions of the previous article [L. Benfatto and M. B. Silva Neto, cond-mat/0602419], with Raman spectroscopy experiments in Sr(2)CuO(2)Cl(2) and untwinned La(2)CuO(4)...
Crystal structure and high-field magnetism of La2CuO4 (2006)
Reehuis, M., Ulrich, C., Prokes, K., Gozar, A., Blumberg, G., Komiya, Seiki, ...
Neutron diffraction was used to determine the crystal structure and magnetic ordering pattern of a La2CuO4 single crystal, with and without applied magnetic field. A previously unreported, subtle...
Crystal structure and high-field magnetism of La2CuO4 (2006)
Reehuis, M., Ulrich, C., Prokeš, K., Gozar, A., Blumberg, G., Komiya, S., ...
Neutron diffraction was used to determine the crystal structure and magnetic ordering pattern of a La2CuO4 single crystal, with and without applied magnetic field. A previously unreported, subtle...
Magnetic and Charge Correlations in La{2-x-y}Nd_ySr_xCuO_4: Raman Scattering Study (2005)
Gozar, A., Komiya, Seiki, Ando, Yoichi, Blumberg, G.
Two aspects in connection with the magnetic properties of La_{2-x-y}Nd_ySr_xCuO_4 single crystals are discussed. The first is related to long wavelength magnetic excitations in x = 0, 0.01, and 0.03...
Electronic Properties of \alpha'-NaV_2O_5 (2005)
We studied electronic excitations in NaV2O5 by Raman. Three main topics are discussed. The first is related to a broad continuum of excitations found in the 200-1500 cm-1 range and peaked around 680...
We study magnetic and electronic properties of two-leg ladder materials. We observed a two-magnon (2M) resonance which we analyze in terms of symmetry, relaxation and resonance properties. Our...
Evolution of Superconductivity in Electron-Doped Cuprates: Magneto-Raman Spectroscopy (2005)
Qazilbash, M. M., Koitzsch, A., Dennis, B. S., Gozar, A., Balci, Hamza, Kendziora, C. A., ...
The electron-doped cuprates Pr_{2-x}Ce_xCuO_4 and Nd_{2-x}Ce_xCuO_4 have been studied by electronic Raman spectroscopy across the entire region of the superconducting (SC) phase diagram. The SC...
Collective Magnetic Excitations in SrCu_2(BO_3)_2 (2005)
We study low temperature Raman data on phononic and magnetic excitations in SrCu_2(BO_3)_2. Regarding the former, in the 0 to 350 cm-1 range we find several pairs of quasi-degenerate modes which have...
Symmetry and light coupling to phononic and collective magnetic excitations in SrCu_2(BO_3)_2 (2005)
Gozar, A., Dennis, B. S., Kageyama, H., Blumberg, G.
We perform a low temperature Raman scattering study of phononic and collective spin excitations in the orthogonal dimers compound SrCu_2(BO_3)_2, focussing on the symmetry and the effects of external...
Hole crystallization in the spin ladder of Sr14Cu24O41 (2005)
Abbamonte, P., Blumberg, G., Rusydi, A., Gozar, A., Evans, P. G., Siegrist, T., ...
One of the deepest questions in condensed matter physics concerns what other phases compete with superconductivity in high-transition-temperature (high-Tc) superconductors. One candidate is the...
Magnetic order in lightly doped La_{2-x}Sr_{x}CuO_{4} (2004)
Gozar, A., Dennis, B. S., Blumberg, G., Komiya, Seiki, Ando, Yoichi
We study long wavelength magnetic excitations in lightly doped La_{2-x}Sr_{x}CuO_{4} (x < 0.03) detwinned crystals. The lowest energy magnetic anisotropy induced gap can be understood in terms of the...
Gozar, A., Dennis, B. S., Siegrist, T., Horibe, Y., Blumberg, G.
Phononic and magnetic Raman scattering are studied in La$_{2-x-y}$Nd$_{y}$Sr$_{x}$CuO$_{4}$ with three doping concentrations: x ~ 1/8, y = 0; x ~ 1/8, y = 0.4; and x = 0.01, y = 0. We observe strong...
Koitzsch, A., Blumberg, G., Gozar, A., Dennis, B. S., Fournier, P., Greene, R. L.
Polarized electronic Raman scattering from the NCCO superconductor at optimal electron doping (T_c=22 K) reveals the formation of an anisotropic pseudogap below a characteristic temperature T* ~ 220...
Gozar, A, Dennis, B.S., Siegrist, T, Horibe, Y, Blumberg, G, Komiya, S, ...
Phononic and magnetic Raman scattering are studied in La2-x-yNdySrxCuO4 with three doping concentrations: x1/8, y = 0; x1/8, y = 0.4; and x = 0.01, y = 0. We observe strong disorder in the tilt...
Sliding Density-Wave in Sr_{14}Cu_{24}O_{41} Ladder Compounds (2002)
Blumberg, G., Littlewood, P., Gozar, A., Dennis, B. S., Motoyama, N., Eisaki, H., ...
We used transport and Raman scattering measurements to identify the insulating state of self-doped spin 1/2 two-leg ladders of Sr_{14}Cu_{24}O_{41} as a weakly pinned, sliding density wave with...
Blumberg, G., Koitzsch, A., Gozar, A., Dennis, B. S., Kendziora, C. A., Fournier, P., ...
We confirm that all the results of scanning SQUID, tunneling, ARPES, penetration depth and Raman experiments are consistent with a nonmonotonic d_{x^2-y^2} superconducting order parameter proposed in...
Collective density wave excitations in two-leg Sr_{14-x}Ca_xCu_{24}O_{41} ladders (2002)
Gozar, A., Blumberg, G., Littlewood, P. B., Dennis, B. S., Motoyama, N., Eisaki, H., ...
Raman measurements in the 1.5 - 20 cm-1 energy range were performed on single crystals of Sr_{14-x}Ca_xCu_{24}O_{41}. A quasielastic scattering peak (QEP) which softens with cooling is observed in...
Raman scattering through surfaces having biaxial symmetry (2002)
Magnetic Raman scattering in two-leg spin ladder materials and the relationship between the anisotropic exchange integrals are analyzed by P. J. Freitas and R. R. P. Singh in Phys. Rev. B, {\bf 62},...
Nonmonotonic d_{x^2-y^2} Superconducting Order Parameter in Nd_{2-x}Ce_xCuO_4 (2002)
Blumberg, G., Koitzsch, A., Gozar, A., Dennis, B. S., Kendziora, C. A., Fournier, P., ...
Low energy polarized electronic Raman scattering of the electron doped superconductor Nd_1.85Ce_0.15CuO_4 (T_c=22 K) has revealed a nonmonotonic d_{x^2-y^2} superconducting order parameter. It has a...
Antiferromagnetism in CaCu$_{3}$Ti$_{4}$O$_{12}$ studied by magnetic Raman spectroscopy (2001)
Koitzsch, A., Blumberg, G., Gozar, A., Dennis, B., Ramirez, A. P., Trebst, S., ...
For CaCu$_{3}$Ti$_{4}$O$_{12}$ -- an insulator that exhibits a giant dielectric response above 100 K -- Cu$^{2+}$ antiferromagnetic spin ordering has been investigated by magnetic Raman scattering...
Spin dynamics of Sr_14Cu_24O_41 two-leg ladder studied by Raman spectroscopy (2001)
Gozar, A., Blumberg, G., Dennis, B. S., Shastry, B. S., Motoyama, N., Eisaki, H., ...
The two-magnon (2M) excitation at 3000 cm-1 in Sr_14Cu_24O_41 two-leg ladder is studied by Raman scattering. A slight anisotropy of the superexchange coupling J_{\perp}/J_{||} \approx 0.8 with J_{||}...