Near-degeneracy of several pairing channels in multiorbital models for the Fe-pnictides (2008)
Graser, S., Maier, T. A., Hirschfeld, P. J., Scalapino, D. J.
Weak-coupling approaches to the pairing problem in the iron pnictide superconductors have predicted a wide variety of superconducting ground states. We argue here that this is due both to the...
Pairing on striped $t$-$t'$-$J$ lattices (2008)
White, Steven R., Scalapino, D. J.
Results are given from a density matrix renormalization group study of pairing on a striped $t$-$t'$-$J$ lattice in the presence of boundary magnetic and pair fields. We find that pairing on a stripe...
Neutron scattering as a probe of the Fe-pnicitide superconducting gap (2008)
Maier, T. A., Scalapino, D. J.
Inelastic neutron scattering provides a probe for studying the spin and momentum structure of the superconducting gap. Here, using a two-orbital model for the Fe-pnicitide superconductors and an...
Modeling of LaO_{1-x}F_xFeAs: the Magnetic Order and Pairing Channels (2008)
Daghofer, M., Moreo, A., Riera, J. A., Arrigoni, E., Scalapino, D. J., Dagotto, E.
A two-orbital model for the LaO_{1-x}F_xFeAs superconductors is investigated using computational techniques on two-dimensional square clusters. The hopping amplitudes are derived from orbital overlap...
Pairing strengths for a two orbital model of the Fe-pnictides (2008)
Qi, Xiao-Liang, Raghu, S., Liu, Chao-Xing, Scalapino, D. J., Zhang, Shou-Cheng
Using an RPA approximation, we have calculated the strengths of the singlet and triplet pairing interactions which arise from the exchange of spin and orbital fluctuations for a 2-orbital model of...
Current-current correlations in the three-band model for two-leg CuO ladders (2008)
Nishimoto, S., Jeckelmann, E., Scalapino, D. J.
We study current-current correlations in the three-band Hubbard model for two-leg CuO ladders using the density-matrix renormalization group method. We find that these correlations decrease...
Graser, S., Boyd, G. R., Cao, Chao, Cheng, Hai-Ping, Hirschfeld, P. J., Scalapino, D. J.
Since the discovery of high-Tc LaO_1-xF_xFeAs, and other such systems based on FeAs layers, several proposals have been made for the superconducting order parameter Delta_k, on both phenomenological...
Pairing Glue in the Hubbard and t-J Models (2008)
Maier, T. A., Poilblanc, D., Scalapino, D. J.
The question of whether one should speak of a "pairing glue" in the Hubbard and t-J models is basically a question about the dynamics of the pairing interaction. If the dynamics of the pairing...
Local quasiparticle lifetimes in a d-wave superconductor (2007)
Graser, S., Hirschfeld, P. J., Scalapino, D. J.
Scanning tunnelling spectroscopy (STS) measurements find that the surface of Bi-2212 is characterized by nanoscale sized regions, "gap patches," which have different magnitudes for the d-wave energy...
Maier, T. A., Macridin, A., Jarrell, M., Scalapino, D. J.
A dynamic cluster quantum Monte Carlo algorithm is used to study a spin susceptibility representation of the pairing interaction for the two-dimensional Hubbard model with an on-site Coulomb...
Evolution of the Spin Gap Upon Doping a 2-Leg Ladder (2007)
Poilblanc, D., Chiappa, O., Riera, J., White, S. R., Scalapino, D. J.
The evolution of the spin gap of a 2-leg ladder upon doping depends upon the nature of the lowest triplet excitations in a ladder with two holes. Here we study this evolution using various numerical...
Calculation of Delta (k,omega) for a 2D t-J cluster (2007)
Poilblanc, Didier, Scalapino, D. J.
Using numerical techniques, the diagonal and off-diagonal superconducting one-electron Green's functions are calculated for a two-dimensional (2D) t-J model on a periodic 32-site cluster at low...
Cold Attractive Spin Polarized Fermi Lattice Gases and the Doped Positive U Hubbard Model (2007)
Moreo, Adriana, Scalapino, D. J.
Experiments on polarized fermion gases performed by trapping ultracold atoms in optical lattices, allow the study of an attractive Hubbard model for which the strength of the on site interaction is...
High energy kink in the single particle spectra of the two-dimensional Hubbard model (2007)
Macridin, Alexandru, Jarrell, M., Maier, Thomas, Scalapino, D. J.
Employing dynamical cluster quantum Monte Carlo calculations we show that the single particle spectral weight A(k,w) of the one-band two-dimensional Hubbard model displays a high energy kink in the...
Probing the pairing symmetry and pair charge stiffness of doped $t-J$ ladders (2006)
Feiguin, A. E., White, S. R., Scalapino, D. J., Affleck, I.
We perform the numerical equivalent of a phase sensitive experiment on doped $t-J$ ladders. We apply proximity effect fields with different complex phases at both ends of an open system and we study...
Maier, T. A., Jarrell, M., Scalapino, D. J.
Using numerical dynamic cluster quantum Monte Carlo results, we study a simple approximation for the pairing interaction of a two-dimensional Hubbard model with an on-site Coulomb interaction $U$...
Distinct Fermi-Momentum Dependent Energy Gaps in Deeply Underdoped Bi2212 (2006)
Tanaka, Kiyohisa, Lee, W. S., Lu, D. H., Fujimori, A., Fujii, T., ...
We use angle-resolved photoemission spectroscopy applied to deeply underdoped cuprate superconductors Bi2Sr2(Ca,Y)Cu2O8 (Bi2212) to reveal the presence of two distinct energy gaps exhibiting...
Feiguin, A. E., White, S. R., Scalapino, D. J.
We present a numerical approach to study the coherent transport of Cooper pairs through a Hubbard chain, and study the role of the contacts in achieving perfect Andreev reflection. We calculate the...
Numerical Studies of the 2D Hubbard Model (2006)
Numerical studies of the two-dimensional Hubbard model have shown that it exhibits the basic phenomena seen in the cuprate materials. At half-filling one finds an antiferromagnetic Mott-Hubbard...
Understanding High-Temperature Superconductors with Quantum Cluster Theories (2006)
Maier, T. A., Jarrell, M. S., Scalapino, D. J.
Quantum cluster theories are a set of approaches for the theory of correlated and disordered lattice systems, which treat correlations within the cluster explicitly, and correlations at longer length...
Woo, Hyungje, Dai, Pengcheng, Hayden, S. M., Mook, H. A., Dahm, T., Scalapino, D. J., ...
Understanding the magnetic excitations in high-transition temperature (high-$T_c$) copper oxides is important because they may mediate the electron pairing for superconductivity. By determining the...
The Pairing Interaction in the 2D Hubbard Model (2006)
Maier, T. A., Jarrell, M., Scalapino, D. J.
A dynamic cluster quantum Monte Carlo approximation is used to study the effective pairing interaction of a 2D Hubbard model with a near neighbor hopping $t$ and an on-site Coulomb interaction $U$ ....
Nonlinear current response of one- and two-band superconductors (2005)
Nicol, E. J., Carbotte, J. P., Scalapino, D. J.
We have calculated the nonlinear current of a number of single band s-wave electron-phonon superconductors. Among issues considered were those of dimensionality, strong electron-phonon coupling,...
The Structure of the Pairing Interaction in the 2D Hubbard Model (2005)
Maier, T. A., Jarrell, M. S., Scalapino, D. J.
Dynamic cluster Monte Carlo calculations for the doped two-dimensional Hubbard model are used to study the irreducible particle-particle vertex responsible for $d_{x^2-y^2}$ pairing in this model....
Inhomogeneity Induces Resonance Coherence Peaks in Superconducting BSCCO (2005)
Fang, A. C., Capriotti, L., Scalapino, D. J., Kivelson, S. A., Kaneko, N., Greven, M., ...
In this paper we analyze, using scanning tunneling spectroscopy, the density of electronic states in nearly optimally doped BSCCO in zero field. Focusing on the superconducting gap, we find patches...
Nodal Quasiparticle Lifetimes in Cuprate Superconductors (2005)
Dahm, T., Hirschfeld, P. J., Scalapino, D. J., Zhu, L.
A new generation of angular-resolved photoemission spectroscopy (ARPES) measurements on the cuprate superconductors offer the promise of enhanced momentum and energy resolution. In particular, the...
Anomaly at Delta_k in the ARPES spectrum of dirty superconductors (2004)
Dahm, T., Hirschfeld, P. J., Zhu, L., Scalapino, D. J.
Elastic forward scattering can lead to an anomaly in the ARPES spectrum of the cuprate superconductors. Here we discuss how this anomaly can be used to provide a measurement of the superconducting...
Nonlinear microwave response of MgB2 (2004)
We calculate the intrinsic nonlinear microwave response of the two gap superconductor MgB2 in the clean and dirty limits. Due to the small value of the pi band gap, the nonlinear response at low...
Relating STM, ARPES, and Transport in the Cuprate Superconducting State (2004)
Scalapino, D. J., Nunner, T. S., Hirschfeld, P. J.
We discuss a wealth of data from various types of experiments which together suggest that the superconducting state of optimally to overdoped BSCCO-2212 can be well-described by the BCS theory with a...
Persistent superfluid phase in a three-dimensional quantum XY model with ring exchange (2004)
Melko, R. G., Scalapino, D. J.
We present quantum Monte Carlo simulation results on a quantum S=1/2 XY model with ring exchange (the J-K model) on a three-dimensional simple cubic lattice. We first characterize the ground state...
Checkerboard patterns in the t-J model (2004)
White, Steven R., Scalapino, D. J.
Using the density matrix renormalization group, we study the possibility of real space checkerboard patterns arising as the ground states of the t-J model. We find that checkerboards with a...
Elastic forward scattering in the cuprate superconducting state (2004)
Zhu, L., Hirschfeld, P. J., Scalapino, D. J.
We investigate the effect of elastic forward scattering on the ARPES spectrum of the cuprate superconductors. In the normal state, small angle scattering from out-of-plane impurities is thought to...
Two-Dimensional Quantum XY Model with Ring Exchange and External Field (2003)
Melko, R. G., Sandvik, A. W., Scalapino, D. J.
We present the zero-temperature phase diagram of a square lattice quantum spin 1/2 XY model with four-site ring exchange in a uniform external magnetic field. Using quantum Monte Carlo techniques, we...
Sandvik, A. W., Scalapino, D. J., Bickers, N. E.
We analyze the effects of an electron-phonon interaction on the one-electron spectral weight A(k,omega) of a d_{x^2-y^2} superconductor. We study the case of an Einstein phonon mode with various...
Stripes on a 6-Leg Hubbard Ladder (2003)
White, Steven R., Scalapino, D. J.
While DMRG calculations find stripes on doped n-leg t-J ladders, little is known about the possible formation of stripes on n-leg Hubbard ladders. Here we report results for a 7x6 Hubbard model with...
Electron-phonon vertex in the two-dimensional one-band Hubbard model (2003)
Huang, Z. B., Hanke, W., Arrigoni, E., Scalapino, D. J.
Using quantum Monte Carlo techniques, we study the effects of electronic correlations on the effective electron-phonon (el-ph) coupling in a two-dimensional one-band Hubbard model. We consider a...
Superconducting gap for a 2-leg t-J ladder (2003)
Poilblanc, Didier, Scalapino, D. J., Capponi, Sylvain
Single-particle diagonal and off-diagonal Green's functions of a 2-leg t-J ladder at 1/8-doping are investigated by Exact Diagonalisations techniques. A numerically tractable expression for the...
Aspect-ratio dependence of the spin stiffness of a two-dimensional XY model (2003)
Melko, R. G., Sandvik, A. W., Scalapino, D. J.
We calculate the superfluid stiffness of 2D lattice hard-core bosons at half-filling (equivalent to the S=1/2 XY-model) using the squared winding number quantum Monte Carlo estimator. For L_x x L_y...
Capriotti, L., Scalapino, D. J., Sedgewick, R. D.
A weak scattering potential imposed on a $CuO_2$ layer of a cuprate superconductor modulates the local density of states $N(x,\omega)$. In recently reported experimental studies scanning-tunneling...
Sedgewick, R. D., Scalapino, D. J., Sugar, R. L., Capriotti, L.
We show how canonical ensemble expectation values can be extracted from quantum Monte Carlo simulations in the grand canonical ensemble. In order to obtain results for all particle sectors, a modest...
Differences Between Hole and Electron Doping of a Two-Leg CuO Ladder (2002)
Nishimoto, S., Jeckelmann, E., Scalapino, D. J.
Here we report results of a density-matrix-renormalization-group (DMRG) calculation of the charge, spin, and pairing properties of a two-leg CuO Hubbard ladder. The outer oxygen atoms as well as the...
Striped phase in a quantum XY-model with ring exchange (2002)
Sandvik, A. W., Daul, S., Singh, R. R. P., Scalapino, D. J.
We present quantum Monte Carlo results for a square-lattice S=1/2 XY-model with a standard nearest-neighbor coupling J and a four-spin ring exchange term K. Increasing K/J, we find that the ground...
Calculation of Delta (k,omega) for a 2D t-J cluster (2002)
Poilblanc, Didier, Scalapino, D. J.
Using numerical techniques, the diagonal and off-diagonal superconducting one-electron Green's functions are calculated for a two-dimensional (2D) t-J model on a periodic 32-site cluster at low...
Superconducting Microwave Pulse Amplifier. (2002)
Birx,D. L., Dick,G. J., Little,W. A., Mercereau,J. E., Scalapino,D. J.
This report summarizes the preliminary research and development of a new and novel technique for very high power microwave pulse amplification. The technique is based on the principle of time...
Electronic Correlations Near a Peierls-CDW Transition (2001)
Monthoux, P., Scalapino, D. J.
Results of a phenomenological Monte carlo calculation for a 2D electron-phonon Holstein model near a Peierls-CDW transition are presented. Here the zero Matsubara frequency part of the phonon action...
Pair Phase Fluctuations and the Pseudogap (2001)
Eckl, T., Scalapino, D. J., Arrigoni, E., Hanke, W.
The single-particle density of states and the tunneling conductance are studied for a two-dimensional BCS-like Hamiltonian with a d_{x^2-y^2}-gap and phase fluctuations. The latter are treated by a...
The 2-Leg Hubbard Ladder: Computational Studies of New Materials (2001)
Computational studies of basic models of strongly-correlated electron systems can provide guidance in the search for new materials as well as insight into the physical mechanisms responsible for...
Rung-Rung Current Correlations on a 2-Leg t-J Ladder (2001)
Scalapino, D. J., White, S. R., Affleck, I.
We report the results of numerical calculations of rung-rung current correlations on a 2-leg t-J ladder with J/t=0.35 for dopings x=0.125 and x=0.19. We find that the amplitude of these correlations...
Fractionalized Phase in an XY-Z_2 Gauge Model (2000)
Sedgewick, R. D., Scalapino, D. J., Sugar, R. L.
We study a model with fractional quantum numbers using Monte Carlo techniques. The model is composed of bosons interacting though a $Z_2$ gauge field. We find that the system has three phases: a...
A New Approach to Doped Mott Insulators (2000)
Bickers, N. E., Scalapino, D. J.
We describe a new microscopic approach for analyzing interacting electron systems with local moments or, in principle, any local order parameter. We specialize attention to the doped Mott insulator...
Some Recent Issues in Quantum Magnetism (2000)
Singh, R. R. P., Pickett, W. E., Hone, D. W., Scalapino, D. J.
Summary of Quantum Magnetism Conference, Institute for Theoretical Physics, University of California, Santa Barbara, California, August 16-20, 1999.
White, Steven R., Scalapino, D. J.
Experiments show evidence for stripe formation in the underdoped cuprates. Here we discuss recent numerical calculations on the t-J model which tell us about the mechanism responsible for stripe...
Evolution of the Spin Gap Upon Doping a 2-Leg Ladder (2000)
Poilblanc, D., Chiappa, O., Riera, J., White, S. R., Scalapino, D. J.
The evolution of the spin gap of a 2-leg ladder upon doping depends upon the nature of the lowest triplet excitations in a ladder with two holes. Here we study this evolution using various numerical...
Phase separation in t-J ladders (1999)
Rommer, Stefan, White, Steven R., Scalapino, D. J.
The phase separation boundary of isotropic t-J ladders is analyzed using density matrix renormalization group techniques. The complete boundary to phase separation as a function of J/t and doping is...
Frustrated Hubbard ladders and superconductivity in $\kappa$-BEDT-TTF organic compounds (1999)
Half-filled two-leg Hubbard ladders have spin-gapped short-range antiferromagnetic correlations while three-leg ladders have power law antoferromagnetic correlations, and both systems have...
Effect of the W-term for a t-U-W Hubbard ladder (1999)
Daul, S., Scalapino, D. J., White, Steven R.
Antiferromagnetic and d_{x2-y2}-pairing correlations appear delicately balanced in the 2D Hubbard model. Whether doping can tip the balance to pairing is unclear and models with additional...
Phase Transitions Between Topologically Distinct Gapped Phases in Isotropic Spin Ladders (1999)
Kim, Eugene H., Fath, G., Solyom, J., Scalapino, D. J.
We consider various two-leg ladder models exhibiting gapped phases. All of these phases have short-ranged valence bond ground states, and they all exhibit string order. However, we show that...
Nonlinear Current Response of a d-wave Superfluid (1999)
Despite several efforts the nonlinear Meissner effect in d-wave superconductors, as has been discussed by Yip and Sauls in 1992, has not been verified experimentally in high-Tc superconductors at...
Superconductivity and Spin Fluctuations (1999)
The organizers of the Memorial Session for Herman Rietschel asked that I review some of the history of the interplay of superconductivity and spin fluctuations. Initially, Berk and Schrieffer showed...
Phase separation and stripe formation in the 2D t-J model: a comparison of numerical results (1999)
White, Steven R., Scalapino, D. J.
We make a critical analysis of numerical results for and against phase separation and stripe formation in the t-J model. We argue that the frustrated phase separation mechanism for stripe formation...
Pairing Correlations on t-U-J Ladders (1999)
Daul, S., Scalapino, D. J., White, Steven R.
Pairing correlations on generalized t-U-J two-leg ladders are reported. We find that the pairing correlations on the usual t-U Hubbard ladder are significantly enhanced by the addition of a...
Comment on ``Stripes and the t-J Model'' (1999)
White, Steven R., Scalapino, D. J.
This is a comment being submitted to Physical Review Letters on a recent letter by Hellberg and Manousakis on stripes in the t-J model.
Microwave Intermodulation in High-Tc Superconducting Microstrip Resonators (1999)
Superconducting Microstrip Resonators, Balam A. Willemsen, B. H. King, T. Dahm, D. J. Scalapino
We present experimental results on microwave intermodulation measurements on a High Tc Superconducting band-reject microstrip resonator which exhibits unconventional 2:1 intermodulation products. We...
Competition Between Stripes and Pairing in a t-t'-J Model (1998)
White, Steven R., Scalapino, D. J.
As the number of legs n of an n-leg, t-J ladder increases, density matrix renormalization group calculations have shown that the doped state tends to be characterized by a static array of domain...
Statistical Mechanics of One-Dimensional Ginzburg-Landau Fields. (1998)
Ferrell,Richard A., Scalapino,D. J., Sears,M.
The statistical mechanics of one-dimensional Ginzburg-Landau fields has been investigated for real, complex, and phase-only fields. (Author)
Nonequilibrium Properties of Superconductivity Induced by Nuclear Radiation. (1998)
Dick,G. J., Mercereau,J. E., Owen,C. W., Scalapino,D. J., Shepard,K. W.
The report is primarily an examination of certain of the dynamic effects associated with the interaction of energetic nuclear particles with the superconducting state. Also included is a brief...
Diagonal Ladders: A New Class of Models for Strongly Coupled Electron Systems (1998)
Sierra, G., Martin-Delgado, M. A., White, S. R., Scalapino, D. J., Dukelsky, J.
We introduce a class of models defined on ladders with a diagonal structure generated by $n_p$ plaquettes. The case $n_p=1$ corresponds to the necklace ladder and has remarkable properties which are...
Comparison of different ladder models (1998)
Jeckelmann, E., Scalapino, D. J., White, S. R.
Using density matrix renormalization group calculations, we compare results obtained for the t-J, one-band Hubbard and three-band Hubbard models of a two-leg CuO ladder. Spin and charge gaps, pair...
Scalapino, D. J., White, Steven R.
For the traditional low T_c superconductors, the superconducting condensation energy is proportional to the change in energy of the ionic lattice between the normal and superconducting state,...
Energetics of Domain Walls in the 2D t-J model (1998)
White, Steven R., Scalapino, D. J.
Using the density matrix renormalization group, we calculate the energy of a domain wall in the 2D t-J model as a function of the linear hole density \rho_\ell, as well as the interaction energy...
The Dimer-Hole-RVB State of the 2-Leg t-J Ladder: A Recurrent Variational Ansatz (1997)
Sierra, G., Martin-Delgado, M. A., Dukelsky, J., White, S. R., Scalapino, D. J.
We present a variational treatment of the ground state of the 2-leg t-J ladder, which combines the dimer and the hard-core boson models into one effective model. This model allows us to study the...
Ground State Properties of the Doped 3-Leg t-J Ladder (1997)
White, Steven R., Scalapino, D. J.
Results for a doped 3-leg t-J ladder obtained using the density matrix renormalization group are reported. At low hole doping, the holes form a dilute gas with a uniform density. The momentum...
Assaad, F. F., Imada, M., Scalapino, D. J.
To the Hubbard model on a square lattice we add an interaction, $W$, which depends upon the square of a near-neighbor hopping. We use zero temperature quantum Monte Carlo simulations on lattice sizes...
DMRG Study of the Striped Phase in the 2D t-J model (1997)
White, Steven R., Scalapino, D. J.
Using the density matrix renormalization group (DMRG), we study the 2D t-J model at a hole doping of x=1/8 on clusters as large as 19x8. We find a striped phase which is consistent with recent...
Spontaneous Flux and Magnetic Interference Patterns in 0-pi Josephson Junctions (1997)
Kirtley, J. R., Moler, K. A., Scalapino, D. J.
The spontaneous flux generation and magnetic field modulation of the critical current in a 0-pi Josephson junction are calculated for different ratios of the junction length to the Josephson...
Enhanced d_{x^2-y^2} pairing correlations in the two-leg Hubbard ladder (1996)
Noack, R. M., Bulut, N., Scalapino, D. J., Zacher, M. G.
The two-leg Hubbard ladder is characterized by the ratio of the inter- to intra-leg hopping t_perp/t, the relative interaction strength U/t and the electron filling. Here, using density matrix...
Monte Carlo study of the pairing interaction in the two-leg Hubbard ladder (1996)
Bulut, N., Dahm, T., Scalapino, D. J.
Monte Carlo calculations of the irreducible particle-particle interaction on a two-leg Hubbard ladder doped near half-filling are reported. As the temperature is lowered, this interaction develops...
d_{x^2-y^2} Pair Domain Walls (1996)
White, Steven R., Scalapino, D. J.
Using the density matrix renormalization group, we study domain wall structures in the t-J model at a hole doping of x=1/8. We find that the domain walls are composed of d_{x^2-y^2} pairs and that...
Weak-coupling calculation of the gap structure of doped n-leg Hubbard ladders (1996)
In weak coupling, the spin gap in doped, even, n-leg periodic Hubbard ladders reflects the energy to break a pair into separate quasiparticles. Here we investigate the structure of the gap within a...