Magnetic mechanism of quasiparticle pairing in hole-doped cuprate superconductors (2008)
We have computed alpha^2F's for the hole-doped cuprates within the framework of the one-band Hubbard model, where the full magnetic response of the system is treated properly. The d-wave pairing...
Appearance of Universal Metallic Dispersion in a Doped Mott Insulator (2008)
Sahrakorpi, S., Markiewicz, R. S., Lin, Hsin, Lindroos, M., Zhou, X. J., Yoshida, T., ...
We have investigated the dispersion renormalization $Z_{disp}$ in La$_{2-x}$Sr$_x$CuO$_4$ (LSCO) over the wide doping range of $x=0.03-0.30$, for binding energies extending to several hundred meV's....
Strong correlation effects and optical conductivity in electron doped cuprates (2008)
Das, Tanmoy, Markiewicz, R. S., Bansil, A.
We demonstrate that most features ascribed to strong correlation effects in various spectroscopies of the cuprates are captured by a calculation of the self-energy incorporating effects of spin and...
Nieminen, Jouko, Lin, Hsin, Markiewicz, R. S., Bansil, A.
We have developed a material specific theoretical framework for modelling scanning tunneling spectroscopy (STS) of high temperature superconducting materials in the normal as well as the...
Resonant Inelastic X-ray Scattering (RIXS) Spectra for Ladder Cuprates (2008)
Al-Sawai, W., Markiewicz, R. S., Hasan, M. Z., Bansil, A.
The ladder compound Sr$_{14}$Cu$_{24}$O$_{41}$ is of interest both as a quasi-one-dimensional analog of the superconducting cuprates and as a superconductor in its own right when Sr is substituted by...
Das, Tanmoy, Markiewicz, R. S., Bansil, A.
We discuss evolution of the Fermi surface (FS) topology with doping in electron doped cuprates within the framework of a one-band Hubbard Hamiltonian, where antiferromagnetism and superconductivity...
A competing order scenario of two-gap behavior in hole doped cuprates (2007)
Das, Tanmoy, Markiewicz, R. S., Bansil, A.
Angle-dependent studies of the gap function provide evidence for the coexistence of two distinct gaps in hole doped cuprates, where the gap near the nodal direction scales with the superconducting...
Li, Y. W., Qian, D., Wray, L., Hsieh, D., Kaga, Y., Sasagawa, T., ...
Momentum resolved inelastic resonant x-ray scattering is used to map the evolution of charge excitations over a large range of energies, momenta and doping levels in the electron doped Mott insulator...
Das, Tanmoy, Markiewicz, R. S., Bansil, A.
We have investigated the doping dependence of the penetration depth vs. temperature in electron doped Pr$_{2-x}$Ce$_x$CuO$_{4-\delta}$ using a model which assumes the uniform coexistence of...
Paramagnon-induced dispersion anomalies in the cuprates (2007)
Markiewicz, R. S., Sahrakorpi, S., Bansil, A.
We report the self-energy associated with RPA magnetic susceptibility in the hole-doped Bi_2Sr_2CuO_6 (Bi2201) and the electron-doped Nd_{2-x}Ce_xCuO_4 (NCCO) in the overdoped regime within the...
Dispersion anomalies induced by the low-energy plasmon in the cuprates (2007)
We discuss the characteristic effects of the electron plasmon interaction resulting from the ~ 1 eV plasmon, which is a universal feature in the cuprates. Using the framework of a one-band tight...
The hierarchy of multiple many-body interaction scales in high-temperature superconductors (2006)
Meevasana, W., Zhou, X. J., Sahrakorpi, S., Lee, W. S., Yang, W. L., Tanaka, K., ...
To date, angle-resolved photoemission spectroscopy has been successful in identifying energy scales of the many-body interactions in correlated materials, focused on binding energies of up to a few...
Effect of Hole Doping on the Electronic Structure of Tl2201 (2006)
Sahrakorpi, S., Lin, Hsin, Markiewicz, R. S., Bansil, A.
We discuss doping dependencies of the electronic structure and Fermi surface of the monolayer Tl$_{2-x}$Cu$_x$Ba$_2$CuO$_{6+\delta}$ (Tl2201). The TlO bands are found to be particularly sensitive to...
Das, Tanmoy, Markiewicz, R. S., Bansil, A.
Recent experiments on Pr$_{0.89}$LaCe$_{0.11}$CuO$_4$ observe an anisotropic spin-correlation gap and a nonmonotonic superconducting (SC) gap, which we analyze within the framework of a...
How different Fermi surface maps emerge in photoemission from Bi2212 (2005)
Asensio, M. C., Avila, J., Roca, L., Tejeda, A., Gu, G. D., Lindroos, M., ...
We report angle-resolved photoemission spectra (ARPES) from the Fermi energy ($E_F$) over a large area of the ($k_x,k_y$) plane using 21.2 eV and 32 eV photons in two distinct polarizations from an...
We present a three-band Hubbard Hamiltonian and the associated Cu K-edge RIXS spectra for electron and hole doped cuprates over a wide range of energy and momentum transfers. By comparing computed...
Lin, Hsin, Sahrakorpi, S., Markiewicz, R. S., Bansil, A.
The Fermi surface (FS) of Bi$_2$Sr$_2$CaCu$_2$O$_{8+\delta}$ (Bi2212) predicted by band theory displays Bi-related pockets around the $(\pi,0)$ point, which have never been observed experimentally....
Markiewicz, R. S., Sahrakorpi, S., Lindroos, M., Lin, Hsin, Bansil, A.
We discuss the effects of interlayer hopping and the resulting $k_z$-dispersion in the cuprates within the framework of the one-band tight binding (TB) model Hamiltonian. Specific forms of the...
Evolution of Mid-gap States and Residual 3-Dimensionality in La$_{2-x}$Sr$_x$CuO$_4$ (2005)
Sahrakorpi, S., Lindroos, M., Markiewicz, R. S., Bansil, A.
We have carried out extensive first principles doping-dependent computations of angle-resolved photoemission (ARPES) intensities in La$_{2-x}$Sr$_x$CuO$_4$ (LSCO) over a wide range of binding...
Bansil, A., Lindroos, M., Sahrakorpi, S., Markiewicz, R. S.
Angle-resolved photoemission spectroscopy (ARPES) presents significant simplications in analyzing strictly two-dimensional (2D) materials, but even the most anisotropic physical systems display some...
Matrix Element and Strong Electron Correlation Effects in ARPES from Cuprates (2004)
Bansil, A., Markiewicz, R. S., Kusko, C., Lindroos, M., Sahrakorpi, S.
We discuss selected results from our recent work concerning the ARPES (angle-resolved photoemission) spectra from the cuprates. Our focus is on developing an understanding of the effects of the ARPES...
A simple antiferromagnetic approach to the Mott transition was recently shown to provide a satisfactory explanation for the Mott gap collapse with doping observed in photoemission experiments on...
A mode coupling calculation which previously explained the Mott gap collapse induced in cuprates by electron doping is applied to the analogous problem of hole doping. A plateau in the q-space...
Bridging k- and q- Space in the Cuprates: Comparing ARPES and STM Results (2003)
A critical comparison is made between the ARPES-derived spectral function and STM studies of Friedel-like oscillations in Bi_2Sr_2CaCu_2O_{8+delta} (Bi2212). The data can be made approximately...
Self-Consistent Renormalization Model of Mott Gap Collapse in the Cuprates (2003)
A generalized antiferromagnetic approach to the Mott transition is analyzed with special emphasis on electron doped cuprates, where evidence for electronic phase separation is weak or absent....
Contrasting Pathways to Mott Gap Collapse in Electron and Hole Doped Cuprates (2003)
Recent ARPES measurements on the electron-doped cuprate Nd_{2-x}Ce_xCuO_4 can be interpreted in a mean field model of uniform doping of an antiferromagnet, with the Mott gap closing near optimal...
Quantum Critical Point in Electron-Doped Cuprates (2002)
Kusko, C., Markiewicz, R. S., Lindroos, M., Bansil, A.
We analyze doping dependent spectral intensities and Fermi surface maps obtained recently in Nd$_{2-x}$Ce$_x$CuO$_{4\pm\delta}$ (NCCO) via high resolution ARPES measurements, and show that the...
Electronic Properties of Intercalated Graphite and Amorphous Metals. (2002)
Markiewicz,R. S., McKnight,S. W., Tsai,C. L.
A general solution has been proposed to the problem of resolving the fundamental Fermi surface sections from magnetooscillations in graphite acceptor compounds, allowing quantitative measure of...
How different Fermi surface maps emerge in photoemission from Bi2212 (2001)
Asensio, M. C., Avila, J., Roca, L., Tejeda, A., Gu, G. D., Lindroos, M., ...
We report angle-resolved photoemission spectra (ARPES) from the Fermi energy ($E_F$) over a large area of the ($k_x,k_y$) plane using 21.2 eV and 32 eV photons in two distinct polarizations from an...
Two Pseudogaps in the Cuprates (2001)
Meingast, et al. suggest that in YBCO the pseudogap is associated with preformed pairs. It is shown that in underdoped cuprates there is evidence for two pseudogaps, and superconducting fluctions...
Chaos in a Jahn-Teller Molecule (2001)
The Jahn-Teller system E x b_1 + b_2 has a particular degeneracy, where the vibronic potential has an elliptical minimum. In the general case where the ellipse does not reduce to a circle, the...
Flux Phase as a Dynamic Jahn-Teller Phase: Berryonic Matter in the Cuprates? (2001)
There is considerable evidence for some form of charge ordering on the hole-doped stripes in the cuprates, mainly associated with the low-temperature tetragonal phase, but with some evidence for...
Berryonic Matter in the Cuprates (2001)
A novel form of Jahn-Teller (JT) effect in the cuprates can be reinterpreted as a conventional JT effect on a lattice with a larger unit cell. There is a triplet of instabilities, parametrized by a...
Phase Separation Models for Cuprate Stripe Arrays (2001)
An electronic phase separation model provides a natural explanation for a large variety of experimental results in the cuprates, including evidence for both stripes and larger domains, and a...
White-Scalapino-like Stripes in a Mean-Field Hubbard Model (2001)
A mean field calculation of the Hubbard model finds a rich phase diagram. The antiferromagnetic phase is generally unstable away from half filling, and there are several regions of phase separation....
Photoemission from Ordered Stripe Phases (2001)
A phase separation model for stripes has found good agreement with photoemission experiments and with other studies which suggest a termination of the striped phase in the slightly overdoped regime....
Kusko, C., Zhai, Z., Markiewicz, R. S., Sridhar, S.
We determine the scattering rate from microwave measurements for an optimally doped Bi-2212 single crystal, using a simple two fluid model with a d-wave symmetry order parameter. In the...
How different Fermi surface maps emerge in photoemission from Bi2212 (2001)
Asensio, M. C., Avila, J., Roca, L., Tejeda, A., Gu, G. D., Lindroos, M., ...
We report angle-resolved photoemission spectra (ARPES) from the Fermi energy ($E_F$) over a large area of the ($k_x,k_y$) plane using 21.2 eV and 32 eV photons in two distinct polarizations from an...
How different Fermi surface maps emerge in photoemission from Bi2212 (2001)
Asensio, M. C., Avila, J., Roca, L., Tejeda, A., Gu, G. D., Lindroos, M., ...
We report angle-resolved photoemission spectra (ARPES) from the Fermi energy ($E_F$) over a large area of the ($k_x,k_y$) plane using 21.2 eV and 32 eV photons in two distinct polarizations from an...
Cluster Spin Glass Distribution Functions in La$_{2-x}$Sr$_x$CuO$_4$ (2000)
Markiewicz, R. S., Cordero, F., Paolone, A., Cantelli, R.
Signatures of the cluster spin glass have been found in a variety of experiments, with an effective onset temperature $T_{on}$ that is frequency dependent. We reanalyze the experimental results and...
(2000) 341-344 [59] A Compton scattering study of insulating PrBa (2000)
A. Erb, B. Revaz, T. Buslaps, V. Honki Maki, E. D. Isaacs, A. Shukla, ...
bel, F. Steglich and M. Peter, Phys. Rev. B 55 (1997) 11714-11721 [49] Stochastic Gradient Approximation: An Efficient Method to Optimize Many-body Wave Functions A. Harju, B. Barbiellini, S....
A Fermi Surface study of Ba$_{1-x}$K$_{x}$BiO$_{3}$ (1999)
Sahrakorpi, S., Barbiellini, B., Markiewicz, R. S., Kaprzyk, S., Lindroos, M., Bansil, A.
We present all electron computations of the 3D Fermi surfaces (FS's) in Ba$_{1-x}$K$_{x}$BiO$_{3}$ for a number of different compositions based on the selfconsistent Korringa-Kohn-Rostoker...
Dispersion of Ordered Stripe Phases in the Cuprates (1999)
A phase separation model is presented for the stripe phase of the cuprates, which allows the doping dependence of the photoemission spectra to be calculated. The idealized limit of a well-ordered...
SO(6)-Generalized Pseudogap Model of the Cuprates (1999)
Markiewicz, R. S., Kusko, C., Vaughn, M. T.
The smooth evolution of the tunneling gap of Bi_2Sr_2CaCu_2O_8 with doping from a pseudogap state in the underdoped cuprates to a superconducting state at optimal and overdoping reflects an...
Stripe Disordering Transition (1999)
Markiewicz, R. S., Vaughn, M. T.
We have recently begun Monte Carlo simulations of the dynamics of stripe phases in the cuprates. A simple model of spinodal decomposition of the holes allows us to incorporate Coulomb repulsion and...
Remnant Fermi Surfaces in Photoemission (1999)
Recent experiments have introduced a new concept for analyzing the photoemission spectra of correlated electrons -- the remnant Fermi surface (rFs), which can be measured even in systems which lack a...
Superlattice Effects in Graphite Intercalation Compounds. (1998)
A new kind of two-dimensional, field-induced phase transition has been discovered in diatomic bromine graphite intercalation compounds. Similar to, but much more pronounced than Condon domain...
Optical Reflectivity Studies of Magnetically Oriented YBa2Cu3O(7-delta). (1998)
Lu, C. F., Perry, C. H., Chen, K., Markiewicz, R. S.
The optical reflectivity spectra of magnetically oriented YBa2Cu3O(7-delta) are reported over a wide energy range from 50 to 24000 wavenumbers (6 meV to 3 eV). A strong optical anisotropy is...
Comment on "Predominantly Superconducting Origin ...", by N. Miyakawa, et al (1998)
Recent tunneling studies in Bi2Sr2CaCu2O8 suggest that the pseudogap is caused by superconducting fluctuations. By reanalyzing this data, we show that instead there is a second non-superconducting...
Higher Symmetries in Condensed Matter Physics (1998)
Markiewicz, R. S., Vaughn, M. T.
We discuss some applications of higher symmetry groups to condensed matter systems. We give special attention to the groups SO(n) (n = 4, 5, 6, 8) in the two-dimensional Hubbard model and its...
It is suggested that recent experiments provide evidence for modulations along the charged stripes in the striped phase of the cuprates. Furthermore, 1/8 doping is special because it is associated...
Tunneling and Photoemission in an SO(6) Superconductor (1998)
Markiewicz, R. S., Kusko, C., Vaughn, M. T.
Combining the results of tunneling, photoemission and thermodynamic studies, the pseudogap is unambiguously demonstrated to be caused by Van Hove nesting: a splitting of the density of states peak at...
Pinned Balseiro-Falicov Model of Tunneling and Photoemission in the Cuprates (1998)
Markiewicz, R. S., Kusko, C., Kidambi, V.
The smooth evolution of the tunneling gap of Bi_2Sr_2CaCu_2O_8 with doping from a pseudogap state in the underdoped cuprates to a superconducting state at optimal and overdoping, has been interpreted...
The Spectrum-Generating Algebra of the Van Hove Scenario is SO(8) (1998)
Markiewicz, R. S., Vaughn, M. T.
The various nesting and pairing instabilities of the generalized Van Hove scenario can be classified via an SO(8) spectrum-generating algebra. An SO(6) subgroup is an approximate symmetry group of...
Tunneling Studies of Pseudogaps: a Comment (1998)
Recent tunneling observations of a pseudogap in Bi_2Sr_2CaCu_2O_{8+delta} are not necessarily evidence that the pseudogap is associated with superconducting fluctuations. The data are here analyzed...
Stripes, pseudogaps, and SO(6) in the cuprate superconductors (1997)
Markiewicz, R. S., Vaughn, M. T.
We briefly summarize two related calculations. First, we demonstrate that the instabilities (either nesting or pairing) associated with the high-T_c cuprates can be described by an SO(6)...
Stripes, Pseudogaps, and Van Hove Nesting in the Three-band tJ Model (1997)
Slave boson calculations have been carried out in the three-band tJ model for the high-T_c cuprates, with the inclusion of coupling to oxygen breathing mode phonons. Phonon-induced Van Hove nesting...
The Van Hove singularity (VHS) provides a paradigm for the study of the role of peaks in the density of states (dos) on electronic properties. More importantly, it appears to play a major role in the...
A purely ionic interpretation of the tilting mode instabilities in La$_{2-x}$A$ _x$CuO$_4$ (A=Sr,Ba) is shown to be not self-consistent: the dominant factor influencing the doping dependence of the...
Spin-orbit coupling plays a large role in stabilizing the low-temperature orthorhombic phase of La$_{2-x}$Sr$_x$CuO$_4$. It splits the degeneracy of the van Hove singularities (thereby stabilizing...
The possible role of the van Hove singularity (vHs) in stabilizing the low-temperature orthorhombic (LTO) phase transition in La$_{2-x}$\-Sr$_x$\-CuO$_ 4$ (LSCO) is discussed. It is found that the...
The low-temperature orthorhombic (LTO) phase transition in La$_{2-x}$Sr$_x$CuO$_4$ can be interpreted as a dynamic Jahn-Teller effect, in which the degenerate electronic states are associated with...