It is now well established that superconducting cuprates support a charge-density-wave state in the so-called underdoped region of their phase diagram. We investigate the possibility of charge order in the square-lattice Hubbard model, both alone and in coexistence with d-wave superconductivity. The charge order has a period of 4 in one direction, is centered on bonds, and has a d form factor. We use the variational cluster approximation, an approach based on a rigorous variational principle that treats short-range correlations exactly, with two clusters of size 2 × 6 that together tile the infinite lattice and provide a nonbiased unit for a period-4 bond-density wave (BDW). We find that the BDW exists in a finite range of hole doping and increases in strength from U = 5 to U = 8. Its location and intensity depend strongly on the band dispersion. When probed simultaneously with d-wave superconductivity, the energy is sometimes lowered by the presence of both phases, depending on the interaction strength. Whenever they coexist, a pair-density wave (a modulation of superconducting pairing with the same period and form factor as the BDW) also exists.

ER - TY - Generic T1 - Phenomenological theories of the low-temperature pseudogap: Hall number, specific heat, and Seebeck coefficient JF - Phys. Rev. B Y1 - 2017 A1 - Verret, S. A1 - Simard, O. A1 - Charlebois, M. A1 - D. Sénéchal A1 - A.-M. S. Tremblay ER - TY - Generic T1 - Pseudogap-to-metal transition in the anisotropic two-dimensional Hubbard model JF - Physical Review B Y1 - 2017 A1 - Faye, J. P. L. A1 - D. Sénéchal ER - TY - Generic T1 - Subgap structures and pseudogap in cuprate superconductors: Role of density waves JF - Phys. Rev. B Y1 - 2017 A1 - Verret, S A1 - Charlebois, M A1 - D. Sénéchal A1 - A.-M. S. Tremblay AB -In scanning tunneling microscopy conductance curves, the superconducting gap of cuprates is sometimes accompanied by small subgap structures at very low energy. This was documented early on near vortex cores and later at zero magnetic field. Using mean-field toy models of coexisting d-wave superconductivity, d-form-factor density wave, and extended s-wave pair density wave (s PDW), we find agreement with this phenomenon, with s PDW playing a critical role. We explore the high variability of the gap structure with changes in band structure and density wave (DW) wave vector, thus explaining why subgap structures may not be a universal feature in cuprates. In the absence of nesting, nonsuperconducting results never show signs of pseudogap, even for large density wave magnitudes, therefore reinforcing the idea of a distinct origin for the pseudogap, beyond mean-field theory. Therefore, we also briefly consider the effect of DWs on a preexisting pseudogap.

ER - TY - Generic T1 - Kekulé superconductivity and antiferromagnetism on the graphene lattice JF - Phys. Rev. B Y1 - 2016 A1 - Faye, J. P. L. A1 - Diarra, M. N. A1 - D. Sénéchal ER - TY - Generic T1 - Mott transition and magnetism on the anisotropic triangular lattice JF - Phys. Rev. B Y1 - 2016 A1 - Acheche, S. A1 - Reymbaut, A. A1 - Charlebois, M. A1 - D. Sénéchal A1 - A.-M. S. Tremblay ER - TY - Generic T1 - Quantum cluster approach to the spinful Haldane-Hubbard model JF - Phys. Rev. B Y1 - 2016 A1 - Wu, Jingxiang A1 - Faye, Jean Paul Latyr A1 - D. Sénéchal A1 - Maciejko, Joseph ER - TY - Generic T1 - Chiral triplet superconductivity on the graphene lattice JF - Physical Review B Y1 - 2015 A1 - Faye, J. P. L. A1 - P. Sahebsara A1 - D. Sénéchal ER - TY - Generic T1 - d-wave superconductivity in coupled ladders JF - Physical Review B Y1 - 2015 A1 - Faye, J. P. L. A1 - Hassan, S. R. A1 - Sriluckshmy, P. V. A1 - Baskaran, G. A1 - D. Sénéchal ER - TY - Generic T1 - Impurity-induced magnetic moments on the graphene-lattice Hubbard model: An inhomogeneous cluster dynamical mean-field theory study JF - Phys. Rev. B Y1 - 2015 A1 - Charlebois, M. A1 - D. Sénéchal A1 - Gagnon, A.-M. A1 - A.-M. S. Tremblay ER - TY - Generic T1 - Quantum cluster methods: CPT and CDMFT T2 - Many-Body Physics: From Kondo to Hubbard, Lecture Notes of the Autumn School on Correlated Electrons 2015 Y1 - 2015 A1 - D. Sénéchal ED - Pavarini, Eva ED - Koch, Erik ED - Piers Coleman ER - TY - Generic T1 - Topological phases of the Kitaev-Hubbard model at half filling JF - Physical Review B Y1 - 2014 A1 - Faye, J. P. L. A1 - D. Sénéchal A1 - Hassan, S. R. ER - TY - Generic T1 - Absence of Spin Liquid in Nonfrustrated Correlated Systems JF - Physical Review Letters Y1 - 2013 A1 - Hassan, S. R. A1 - D. Sénéchal ER - TY - Generic T1 - Hassan and Sénéchal Reply: JF - Physical Review Letters Y1 - 2013 A1 - Hassan, S. R. A1 - D. Sénéchal ER - TY - Generic T1 - Mott p-n junctions in layered materials JF - Phys. Rev. B Y1 - 2013 A1 - Charlebois, M. A1 - Hassan, S. R. A1 - Karan, R. A1 - D. Sénéchal A1 - A.-M. S. Tremblay ER - TY - Generic T1 - Quarter-filled Kitaev-Hubbard model: A quantum Hall state in an optical lattice JF - Physical Review B Y1 - 2013 A1 - Hassan, S. R. A1 - Goyal, Sandeep A1 - Shankar, R. A1 - D. Sénéchal ER - TY - Generic T1 - Resilience of d-wave superconductivity to nearest-neighbor repulsion JF - Phys. Rev. B Y1 - 2013 A1 - D. Sénéchal A1 - Day, A. G. R. A1 - Bouliane, V. A1 - A.-M. S. Tremblay ER - TY - Generic T1 - Stable Algebraic Spin Liquid in a Hubbard Model JF - Physical Review Letters Y1 - 2013 A1 - Hassan, S. A1 - Sriluckshmy, P. A1 - Goyal, Sandeep A1 - Shankar, R. A1 - D. Sénéchal ER - TY - Generic T1 - Cluster Dynamical Mean Field Theory T2 - Theoretical methods for Strongly Correlated Systems Y1 - 2012 A1 - D. Sénéchal ED - Adolfo Avella ED - Ferdinando Mancini ER - TY - Generic T1 - Cluster Perturbation Theory T2 - Theoretical methods for Strongly Correlated Systems Y1 - 2012 A1 - D. Sénéchal ED - Adolfo Avella ED - Ferdinando Mancini ER - TY - Generic T1 - d-wave superconductivity on the checkerboard Hubbard model at weak and strong coupling JF - Physical Review B Y1 - 2011 A1 - Shiladitya Chakraborty A1 - D. Sénéchal A1 - A.-M. S. Tremblay ER - TY - Generic T1 - Superconductivity in the subatomic realm JF - Physics in Canada/La physique au Canada Y1 - 2011 A1 - D. Sénéchal ER - TY - Generic T1 - Variational cluster approximation study of the one-dimensional Holstein-Hubbard model at half filling JF - Phys. Rev. B Y1 - 2011 A1 - Payeur, Alexandre A1 - D. Sénéchal ER - TY - Generic T1 - Bath optimization in the cellular dynamical mean-field theory JF - Physical Review B Y1 - 2010 A1 - D. Sénéchal KW - Sans titre ER - TY - Generic T1 - Dynamical electronic nematicity from Mott physics JF - Physical Review B (Editor's choice) Y1 - 2010 A1 - Okamoto, S. A1 - D. Sénéchal A1 - Civelli, M. A1 - A.-M. S. Tremblay AB -Very large anisotropies in transport quantities have been observed in the presence of very small in-plane structural anisotropy in many strongly correlated electron materials. By studying the two-dimensional Hubbard model with dynamical-mean-field theory for clusters, we show that such large anisotropies can be induced without static stripe order if the interaction is large enough to yield a Mott transition. Anisotropy decreases at large frequency. The maximum effect on conductivity anisotropy occurs in the underdoped regime, as observed in high-temperature superconductors.

ER - TY - Generic T1 - First-order Mott transition at zero temperature in two dimensions: Variational plaquette study JF - Europhysics Letters Y1 - 2009 A1 - Balzer, M. A1 - B. Kyung A1 - D. Sénéchal A1 - A.-M. S. Tremblay A1 - Potthoff, M. AB -The nature of the metal-insulator Mott transition at zero temperature has been discussed for a number of years. Whether it occurs through a quantum critical point or through a first-order transition is expected to profoundly influence the nature of the finite-temperature phase diagram. In this paper, we study the zero temperature Mott transition in the two-dimensional Hubbard model on the square lattice with the variational cluster approximation. This takes into account the influence of antiferromagnetic short-range correlations. By contrast to single-site dynamical mean-field theory, the transition turns out to be first order even at zero temperature. Copyright (C) EPLA, 2009

ER - TY - Generic T1 - Pairing dynamics in strongly correlated superconductivity JF - Physical Review B Y1 - 2009 A1 - B. Kyung A1 - D. Sénéchal A1 - A.-M. S. Tremblay AB -Confirmation of the phononic origin of Cooper pair formation in superconductors came with the demonstration that the interaction was retarded and that the corresponding energy scales were associated with phonons. Using cellular dynamical mean-field theory for the two-dimensional Hubbard model, we identify such retardation effects in d-wave pairing and associate the corresponding energy scales with short-range spin fluctuations. We find which frequencies are relevant for pairing as a function of interaction strength and doping and show that the disappearance of superconductivity on the overdoped side coincides with the disappearance of the low-energy feature in the antiferromagnetic fluctuations, as observed in neutron-scattering experiments.

ER - TY - Generic T1 - Anomalous superconductivity and its competition with antiferromagnetism in doped Mott insulators JF - Physical Review B Y1 - 2008 A1 - Kancharla, S. S. A1 - B. Kyung A1 - D. Sénéchal A1 - Civelli, M. A1 - Capone, M. A1 - Kotliar, G. A1 - A.-M. S. Tremblay AB -Proximity to a Mott insulating phase is likely to be an important physical ingredient of a theory that aims to describe high-temperature superconductivity in the cuprates. Quantum cluster methods are well suited to describe the Mott phase. Hence, as a step toward a quantitative theory of the competition between antiferromagnetism and d-wave superconductivity in the cuprates, we use cellular dynamical mean-field theory to compute zero-temperature properties of the two-dimensional square lattice Hubbard model. The d-wave order parameter is found to scale like the superexchange coupling J for on-site interaction U comparable to or larger than the bandwidth. The order parameter also assumes a dome shape as a function of doping, while, by contrast, the gap in the single-particle density of states decreases monotonically with increasing doping. In the presence of a finite second neighbor hopping t', the zero-temperature phase diagram displays the electron-hole asymmetric competition between antiferromagnetism and superconductivity that is observed experimentally in the cuprates. Adding realistic third neighbor hopping t '' improves the overall agreement with the experimental phase diagram. Since band parameters can vary depending on the specific cuprate considered, the sensitivity of the theoretical phase diagram to band parameters challenges the commonly held assumption that the doping Vs T-c/T-c(max) phase diagram of the cuprates is universal. The calculated angle-resolved photoemission spectrum displays the observed electron-hole asymmetry. The tendency to homogeneous coexistence of the superconducting and antiferromagnetic order parameters is stronger than observed in most experiments but consistent with many theoretical results and with experiments in some layered high-temperature superconductors. Clearly, our calculations reproduce important features of d-wave superconductivity in the cuprates that would otherwise be considered anomalous from the point of view of the standard Bardeen-Cooper-Schrieffer approach. At strong coupling, d-wave superconductivity and antiferromagnetism naturally appear as two equally important competing instabilities of the normal phase of the same underlying Hamiltonian.

ER - TY - Generic T1 - Convexity of the self-energy functional in the variational cluster approximation JF - Physical Review B Y1 - 2008 A1 - Nevidomskyy, A. H. A1 - D. Sénéchal A1 - A.-M. S. Tremblay AB -In the variational cluster approximation (VCA) (or variational cluster perturbation theory), widely used to study the Hubbard model, a fundamental problem that renders variational solutions difficult in practice is its known lack of convexity at stationary points, i.e., the physical solutions can be saddle points rather than extrema of the self-energy functional. Here, we suggest two different approaches to construct a convex functional Omega[Sigma]. In the first approach, one can show analytically that in the approximation where the irreducible particle-hole vertex depends only on center of mass coordinates, the functional is convex away from phase transitions in the corresponding channel. Numerical tests on a tractable version of that functional show that convexity can be a nuisance when looking for instabilities both in the pairing and particle-hole channels. Therefore, an alternative phenomenological functional is proposed. Convexity is explicitly enforced only with respect to a restricted set of variables, such as the cluster chemical potential that is known to be otherwise problematic. Numerical tests show that our functional is convex at the physical solutions of VCA and allows second-order phase transitions in the pairing channel as well. This opens the way to the use of more efficient algorithms to find solutions of the VCA equations.

ER - TY - Generic T1 - Hubbard Model on the Triangular Lattice: Spiral Order and Spin Liquid JF - Physical Review Letters Y1 - 2008 A1 - P. Sahebsara A1 - D. Sénéchal KW - Sans titre ER - TY - Generic T1 - Magnetism and d-wave superconductivity on the half-filled square lattice with frustration JF - Physical Review B Y1 - 2008 A1 - Nevidomskyy, A. H. A1 - Scheiber, C. A1 - D. Sénéchal A1 - A.-M. S. Tremblay AB -The role of frustration and interaction strength on the half-filled Hubbard model is studied on the square lattice with nearest- and next-nearest-neighbor hoppings t and t(') using the variational cluster approximation (VCA). At half-filling, we find two phases with long-range antiferromagnetic (AF) order: the usual Neel phase, stable at small frustration t(')/t, and the so-called collinear (or superantiferromagnet) phase with ordering wave vector (pi,0) or (0,pi), stable for large frustration. These are separated by a phase with no detectable long-range magnetic order. We also find the d-wave superconducting (SC) phase (d(x)(2)-y(2)), which is favored by frustration if it is not too large. Intriguingly, there is a broad region of coexistence where both AF and SC order parameters have nonzero values. In addition, the physics of the metal-insulator transition in the normal state is analyzed. The results obtained with the help of the VCA method are compared with the large-U expansion of the Hubbard model and known results for the frustrated J(1)-J(2) Heisenberg model. These results are relevant for pressure studies of undoped parents of the high-temperature superconductors: we predict that an insulator to d-wave SC transition may appear under pressure.

ER - TY - Generic T1 - Is SUSY natural? JF - New Journal of Physics Y1 - 2008 A1 - K. Dienes A1 - Michael Lennek A1 - D. Sénéchal A1 - Vaibhav Wasnik KW - Sans titre AB -Space-time supersymmetry (SUSY) is widely believed to play an important role in most fundamental theories of physics, and is usually invoked in order to address problems of naturalness. In this paper, we examine the question of whether SUSY itself is ’natural’ (i.e. likely to exist as a fundamental component of nature at high-energy scales). Our approach to answering this question is based on a statistical examination of the heterotic string landscape, and our conclusion is that SUSY is an exceedingly rare phenomenon. We also find that the likelihood of SUSY appearing at the string scale is dependent on the gauge symmetries present at the string scale, with certain gauge groups strongly favoring the appearance of {\\cal N} = 1 SUSY and others not. This paper summarizes several recent papers, yet also contains some new results. In particular, one new result is that the heterotic landscape appears to favor either the non-supersymmetric Standard Model or an {\\cal N} =1 SUSY GUT gauge group at the string scale; by contrast, the opposite outcomes (namely the minimal supersymmetric Standard Model (MSSM) or a non-supersymmetric GUT) are significantly disfavored.

ER - TY - Generic T1 - The Variational Cluster Approximation for Hubbard Models: Practical Implementation JF - High Performance Computing Systems and Applications, 2008. HPCS 2008. 22nd International Symposium on Y1 - 2008 A1 - D. Sénéchal KW - correlated electron systems KW - frequency- wavevector integrals KW - high-temperature superconductors KW - Hubbard model KW - integral equations KW - lattice sites KW - lattice theory KW - molecular electronic states KW - organic superconductors KW - organic superconductorsHubbard models KW - Sans titre KW - senechal KW - variational cluster approximation ER - TY - Generic T1 - Supersymmetry versus gauge symmetry on the heterotic landscape JF - Phys. Rev. D Y1 - 2007 A1 - K. Dienes A1 - Michael Lennek A1 - D. Sénéchal A1 - Vaibhav Wasnik KW - Sans titre ER - TY - Generic T1 - Antiferromagnetism and Superconductivity in Layered Organic Conductors: Variational Cluster Approach JF - Physical Review Letters Y1 - 2006 A1 - P. Sahebsara A1 - D. Sénéchal KW - Sans titre ER - TY - Generic T1 - d-wave superconductivity, antiferromagnetism and spin liquid in quasi-two-dimensional organic superconductors JF - Iranian Journal of Physics Research Y1 - 2006 A1 - P. Sahebsara A1 - D. Sénéchal KW - Sans titre ER - TY - Generic T1 - Pseudogap and high-temperature superconductivity from weak to strong coupling. Towards a quantitative theory JF - Low Temperature Physics Y1 - 2006 A1 - A.-M. S. Tremblay A1 - B. Kyung A1 - D. Sénéchal AB -This is a short review of the theoretical work on the two-dimensional Hubbard model performed in Sherbrooke in the last few years. It is written on the occasion of the twentieth anniversary of the discovery of high-temperature superconductivity. We discuss several approaches, how they were benchmarked and how they agree sufficiently with each other that we can trust that the results are accurate solutions of the Hubbard model. Then comparisons are made with experiment. We show that the Hubbard model does exhibit d-wave superconductivity and antiferromagnetism essentially where they are observed for both hole- and electron-doped cuprates. We also show that the pseudogap phenomenon comes out of these calculations. In the case of electron-doped high temperature superconductors, comparisons with angle-resolved photoemission experiments are nearly quantitative. The value of the pseudogap temperature observed for these compounds in recent photoemission experiments had been predicted by theory before it was observed experimentally. Additional experimental confirmation would be useful. The theoretical methods that are surveyed include mostly the two-particle self-consistent approach, variational cluster perturbation theory (or variational cluster approximation), and cellular dynamical mean-field theory. (c) 2006 American Institute of Physics.

ER - TY - Generic T1 - Pseudogap induced by short-range spin correlations in a doped Mott insulator JF - Physical Review B Y1 - 2006 A1 - B. Kyung A1 - Kancharla, S. S. A1 - D. Sénéchal A1 - A.-M. S. Tremblay A1 - Civelli, M. A1 - Kotliar, G. AB -We study the evolution of a Mott-Hubbard insulator into a correlated metal upon doping in the two-dimensional Hubbard model using the cellular dynamical mean-field theory. Short-range spin correlations create two additional bands apart from the familiar Hubbard bands in the spectral function. Even a tiny doping into this insulator causes a jump of the Fermi energy to one of these additional bands and an immediate momentum-dependent suppression of the spectral weight at this Fermi energy. The pseudogap is closely tied to the existence of these bands. This suggests a strong-coupling mechanism that arises from short-range spin correlations and large scattering rates for the pseudogap phenomenon seen in several cuprates.

ER - TY - Generic T1 - Strong- and weak-coupling mechanisms for pseudogap in electron-doped cuprates JF - Journal of Physics and Chemistry of Solids Y1 - 2006 A1 - Hankevych, V. A1 - B. Kyung A1 - Dare, A. M. A1 - D. Sénéchal A1 - A.-M. S. Tremblay AB -Using the two-particle self-consistent approach and cluster perturbation theory for the two-dimensional t-t'-t"-U Hubbard model, we discuss weak- and strong-coupling mechanisms for the pseudogap observed in recent angle resolved photoemission spectroscopy on electron-doped cuprates. In the case of the strong-coupling mechanism, which is more relevant near half-filling, the pseudogap can be mainly driven by short-range correlations near the Mott insulator. In the vicinity of optimal doping, where weak-coupling physics is more relevant, large antiferromagnetic correlation lengths, seen in neutron measurements, are the origin of the pseudogap. The t-J model is not applicable in the latter case. (c) 2006 Elsevier Ltd. All rights reserved.

ER - TY - Generic T1 - Competition between Antiferromagnetism and Superconductivity in High-$T_c$ Cuprates JF - Physical Review Letters Y1 - 2005 A1 - D. Sénéchal A1 - P.-L. Lavertu A1 - M.-A. Marois A1 - A.-M. S. Tremblay KW - Sans titre ER - TY - Generic T1 - Hot spots and pseudogaps for hole- and electron-doped high-temperature superconductors JF - Physical Review Letters Y1 - 2004 A1 - D. Sénéchal A1 - A.-M. S. Tremblay AB -Using cluster perturbation theory, it is shown that the spectral weight and pseudogap observed at the Fermi energy in recent angle resolved photoemission spectroscopy of both electron- and hole-doped high-temperature superconductors find their natural explanation within the t-t(')-t('')-U Hubbard model in two dimensions. The value of the interaction U needed to explain the experiments for electron-doped systems at optimal doping is in the weak to intermediate coupling regime where the t-J model is inappropriate. At strong coupling, short-range correlations suffice to create a pseudogap, but at weak-coupling long correlation lengths associated with the antiferromagnetic wave vector are necessary.

ER - TY - Generic T1 - Strong- and weak-coupling mechanisms for pseudogap in electron-doped cuprates T2 - Spectroscopies in Novel Superconductors Y1 - 2004 A1 - Hankevych, Vasyl A1 - Kyung, Bumsoo A1 - Daré, A.-M. A1 - D. Sénéchal A1 - A.-M. S. Tremblay ER - TY - Generic T1 - Theoretical Methods For Strongly Correlated Electrons Y1 - 2004 A1 - S. Allen A1 - A.-M. S. Tremblay A1 - Vilk, Y.M. ED - D. Sénéchal ED - A.-M. S. Tremblay ED - C Bourbonnais AB -The conserving approximation scheme to many-body problems was developed by Kadanoff and Baym using the functional-derivative approach. Another approach for the Hubbard model also satisfies conservation laws, but in addition it satisfies the Pauli principle and a number of sum rules. A concise formal derivation of that approach, using functional derivatives, is given in this conference paper to highlight formal analogies and differences with conserving approximations.

ER - TY - Generic T1 - A cluster method for spectral properties of correlated electrons T2 - High Performance Computing Systems and Applications and OSCAR symposium Y1 - 2003 A1 - D. Sénéchal ED - D. Sénéchal KW - Sans titre ER - TY - Generic T1 - Theoretical Methods for Strongly Correlated Electrons T2 - CRM Series in Mathematical Physics Y1 - 2003 A1 - D. Sénéchal A1 - A.-M. S. Tremblay A1 - C Bourbonnais ER - TY - Generic T1 - What is the Hamiltonian for parent high-temperature superconductors? T2 - 17th annual international symposium on High Performance Computing Systems and Applications and the OSCAR Symposium Y1 - 2003 A1 - Alexis Gagné-Lebrun A1 - A.-M. S. Tremblay ED - D. Sénéchal ER - TY - Generic T1 - Cluster Perturbation Theory for Hubbard models JF - Physical Review B Y1 - 2002 A1 - D. Sénéchal A1 - D. Perez A1 - D. Plouffe KW - Sans titre ER - TY - Generic T1 - Conserving approximations vs Two-Particle Self-Consistent Approach T2 - Theoretical Methods for Strongly Correlated Electrons Y1 - 2001 A1 - S. Allen A1 - A.-M. S. Tremblay A1 - Vilk, Y.M. ED - D. Sénéchal ED - A.-M. S. Tremblay ED - C Bourbonnais ER - TY - Generic T1 - Les mathématiques et la physique du XXème siècle : quelques aspects T2 - Actes du 42e congrès de l’Association mathématique du Québec Y1 - 2000 A1 - D. Sénéchal KW - Sans titre ER - TY - Generic T1 - Spectral Weight of the Hubbard Model through Cluster Perturbation Theory JF - Physical Review Letters Y1 - 2000 A1 - D. Sénéchal A1 - D. Perez A1 - M Pioro-Ladrière KW - Sans titre ER - TY - Generic T1 - The spin-1 ladder : A bosonization study JF - Physical Review B Y1 - 2000 A1 - D. Allen A1 - D. Sénéchal KW - Sans titre ER - TY - Generic T1 - Strong correlations in low dimensional conductors: What are they and where are the challenges? JF - Physics in Canada/La physique au Canada Y1 - 2000 A1 - A.-M. S. Tremblay A1 - C Bourbonnais A1 - D. Sénéchal KW - Sans titre ER - TY - Generic T1 - Strong-coupling perturbation theory of the Hubbard model JF - European Physical Journal B Y1 - 2000 A1 - Pairault, S. A1 - D. Sénéchal A1 - A.-M. S. Tremblay KW - Sans titre AB -The strong-coupling perturbation theory of the Hubbard model is presented and carried out tu order (t/U)(5) for the one-particle Green function In arbitrary dimension. The spectral weight A(k,omega) is expressed as a Jacobi continued fraction and compared with new Monte-Carlo data of the one-dimensional, half-filled Hubbard model. Different regimes (insulator, conductor and short-range antiferromagnet) are identified in the temperature-hopping integral (T, t) plane. This work completes a first paper on the subject (Phys. Rev. Lett. 80, 5389 (1998)) by providing details on diagrammatic rules and higher-order results. In addition, the non half-filled case, infinite resummations of diagrams and the double occupancy are discussed. Various tests: of the method are also presented.

ER - TY - Generic T1 - The Fermi liquid as a Renormalization-Group fixed point: the role of interference in the Landau channel JF - Physical Review B Y1 - 1998 A1 - Chitov, G.Y. A1 - D. Sénéchal KW - Sans titre ER - TY - Generic T1 - SO(5)-Symmetric description of the low-energy sector of a ladder system JF - Physical Review B Y1 - 1998 A1 - D.G. Shelton A1 - D. Sénéchal KW - Sans titre ER - TY - Generic T1 - Strong-coupling expansion for the Hubbard model JF - Physical Review Letters Y1 - 1998 A1 - Pairault, S. A1 - D. Sénéchal A1 - A.-M. S. Tremblay AB -A strong-coupling expansion for models of correlated electrons in any dimension is presented. The method is applied to the Hubbard model in d dimensions and compared with numerical results in d = 1. Third order expansion of the Green's function suffices to exhibit both the Mott metal-insulator transition and a low-temperature regime where antiferromagnetic correlations are strong. It is predicted that some of the weak photoemission signals observed in one-dimensional systems such as SrCuO2 should become stronger as temperature increases away from the spin-charge separated state.

ER - TY - Generic T1 - Thermal phase diagrams of columnar liquid crystals JF - Phys. Rev. E Y1 - 1998 A1 - G. Lamoureux A1 - Caillé, A. A1 - D. Sénéchal KW - Sans titre ER - TY - Generic T1 - Conformal Field Theory Y1 - 1997 A1 - Di Francesco, P. A1 - P. Mathieu A1 - D. Sénéchal KW - Sans titre ER - TY - Generic T1 - Non-Abelian bosonization of the frustrated antiferromagnetic spin-1/2 chain JF - Physical Review B Y1 - 1997 A1 - D. Allen A1 - D. Sénéchal KW - Sans titre ER - TY - Generic T1 - Renormalization-group study of interacting electrons JF - Physical Review B Y1 - 1995 A1 - Chitov, G.Y. A1 - D. Sénéchal KW - Sans titre ER - TY - Generic T1 - Semiclassical description of spin ladders JF - Physical Review B Y1 - 1995 A1 - D. Sénéchal KW - Sans titre ER - TY - Generic T1 - Semiclassical description of the frustrated antiferromagnetic chain JF - Physical Review B Y1 - 1995 A1 - D. Allen A1 - D. Sénéchal KW - Sans titre ER - TY - Generic T1 - Temperature dependence of the ESR spectrum of {$\rm CsNiCl_3$} JF - Physical Review B Y1 - 1995 A1 - Y. Trudeau A1 - D. Sénéchal A1 - Poirier, M. KW - Sans titre ER - TY - Generic T1 - Can fusion coefficients be calculated from the depth rule? JF - Nucl. Phys. B Y1 - 1993 A1 - A.N. Kirillov A1 - P. Mathieu A1 - D. Sénéchal A1 - M. Walton KW - Sans titre ER - TY - Generic T1 - Haldane gap in the quasi-one-dimensional nonlinear $\sigma$ model JF - Physical Review B Y1 - 1993 A1 - D. Sénéchal KW - Sans titre ER - TY - Generic T1 - The mass gap of the nonlinear $\sigma$ model through the finite temperature effective action JF - Physical Review B Y1 - 1993 A1 - D. Sénéchal KW - Sans titre ER - TY - Generic T1 - Chern-Simons superconductivity without parity violation JF - Physics Letters B Y1 - 1992 A1 - D. Sénéchal ER - TY - Generic T1 - Chern-Simons superconductivity without parity violation T2 - Proceedings of the 1992 CAP/NSERC workshop on integrable models, statistical models and quantum group, Kingston (Ontario) Y1 - 1992 A1 - D. Sénéchal ER - TY - Generic T1 - Field identification in nonunitary diagonal cosets JF - Int. J. Mod. Phys. A Y1 - 1992 A1 - P. Mathieu A1 - D. Sénéchal A1 - M. Walton KW - Sans titre ER - TY - Generic T1 - Integrability of the quantum KdV equation at $c= -2$ JF - Modern Physics Letters A Y1 - 1992 A1 - Di Francesco, P. A1 - P. Mathieu A1 - D. Sénéchal KW - Sans titre ER - TY - Generic T1 - Chaos in the Hermitian one-matrix model JF - Int. J. Mod. Phys. A Y1 - 1991 A1 - D. Sénéchal KW - Sans titre ER - TY - Generic T1 - Gravité quantique et modèles de matrices JF - Can. J. Phys. Y1 - 1991 A1 - D. Sénéchal KW - Sans titre ER - TY - Generic T1 - KdV-type equations in subcritical strings T2 - Nonlinear fields: classical, random, semi-classical, Proceedings of the 27th Karpacz winter school of Theoretical Physics Y1 - 1991 A1 - P. Mathieu A1 - D. Sénéchal ED - P. Garbaczewski et Z. Popowicz ER - TY - Generic T1 - Tachyonic Hermitian one-matrix models JF - Modern Physics Letters A Y1 - 1991 A1 - P. Mathieu A1 - D. Sénéchal KW - Sans titre ER - TY - Generic T1 - A well-defined multicritical series in the Hermitian one-matrix model JF - Physics Letters B Y1 - 1991 A1 - P. Mathieu A1 - D. Sénéchal KW - Sans titre ER - TY - Generic T1 - Induced Hopf term in the nonlinear $\sigma$ model JF - Phys. Rev. D Y1 - 1990 A1 - Z. Hlousek A1 - D. Sénéchal A1 - S.-H. Tye KW - Sans titre ER - TY - Generic T1 - Search for four-dimensional string models JF - Phys. Rev. D Y1 - 1989 A1 - D. Sénéchal KW - Sans titre ER - TY - Generic T1 - Construction of four-dimensional string models T2 - Proceedings of the APS Meeting at Salt Lake City Y1 - 1987 A1 - Hikaru Kawai A1 - David C. Lewellen A1 - Joel A. Schwartz A1 - D. Sénéchal A1 - S.-H. Henry Tye ED - Carleton DeTar ED - James Ball ER -