J. Dukelsky

Occupation numbers in self consistent RPA (2006)

A method is proposed which allows to calculate within the SCRPA theory the occupation numbers via the single particle Green function. This scheme complies with the Hugenholtz van Hove theorem. In an...

Occupation numbers in self consistent RPA (2006)

A method is proposed which allows to calculate within the SCRPA theory the occupation numbers via the single particle Green function. This scheme complies with the Hugenholtz van Hove theorem. In an...

Fermion condensation and non Fermi liquid behavior in a model with long range forces (2006)

A method is proposed which allows to calculate within the SCRPA theory the occupation numbers via the single particle Green function. This scheme complies with the Hugenholtz van Hove theorem. In an...

Dukelsky, J., Khodel, V.A., Schuck, P., Shaginyan, V.R.

Fully self-consistent RPA description of the many level pairing model (2006)

Hirsch, J.G., Mariano, A., Dukelsky, J., Schuck, P.

The self-consistent RPA (SCRPA) equations in the particle-particle channel are solved without any approximation for the picket fence model. The results are in excellent agreement with the exact...

Exactly-solvable models of proton and neutron interacting bosons (2006)

H., S. Lerma, Errea, B., Dukelsky, J., Pittel, S., Van Isacker, P.

We describe a class of exactly-solvable models of interacting bosons based on the algebra SO(3,2). Each copy of the algebra represents a system of neutron and proton bosons in a given bosonic level...

Intrinsic state for an extended version of the interacting boson model (2006)

Garcia-Ramos, J.E., Arias, J.M., Dukelsky, J., Van Isacker, P.

What is a Cooper pair ? (2006)

Ortiz, G., Dukelsky, J.

Recently, the nature of Cooper pairs in the BCS-BEC crossover has regained attention due to the observation of a large fraction of preformed fermion pairs on the BCS side of the Feshbach resonance in...

Entanglement in a first order quantum phase transition (2006)

Density matrix renormalization group approach for many-body open quantum systems (2006)

The phase diagram of spins 1/2 embedded in a magnetic field mutually interacting antiferromagnetically is determined. Contrary to the ferromagnetic case where a second order quantum phase transition...

Rotureau, J., Michel, N., Nazarewicz, W., Ploszajczak, M., Dukelsky, J.

The density matrix renormalization group (DMRG) approach is extended to complex-symmetric density matrices characteristic of many-body open quantum systems. Within the continuum shell model, we...

Exact Solution of the Isovector Proton Neutron Pairing Hamiltonian (2006)

Dukelsky, J., Gueorguiev, V. G., Van Isacker, P., Dimitrova, S., Errea, B., H, S. Lerma

The complete exact solution of the T=1 neutron-proton pairing Hamiltonian is presented in the context of the SO(5) Richardson-Gaudin model with non-degenerate single-particle levels and including...

A scalar two-level boson model to study the IBM phase diagram in the Casten triangle (2006)

Vidal, J., Arias, J. M., Dukelsky, J., Garcia-Ramos, J. E.

We introduce a simple two-level boson model with the same energy surface as the Q-consistent Interacting Boson Model Hamiltonian. The model can be diagonalized for large number of bosons and the...

Boson-Fermion pairing in a Boson-Fermion environment (2006)

Storozhenko, A., Schuck, P., Suzuki, T., Yabu, H., Dukelsky, J.

Propagation of a Boson-Fermion (B-F) pair in a B-F environment is considered. The possibility of formation of stable strongly correlated B-F pairs, embedded in the continuum, is pointed out. The new...

Exact Solution of the Isovector Proton Neutron Pairing Hamiltonian (2006)

Dukelsky, J., Gueorguiev, V. G., Van Isacker, P., Dimitrova, S., Errea, B., H, S. Lerma

The complete exact solution of the T=1 neutron-proton pairing Hamiltonian is presented in the context of the SO(5) Richardson-Gaudin model with non-degenerate single-particle levels and including...

Density matrix renormalization group approach for many-body open quantum systems (2006)

Rotureau, J., Michel, N., Nazarewicz, W., Ploszajczak, M., Dukelsky, J.

The density matrix renormalization group (DMRG) approach is extended to complex-symmetric density matrices characteristic of many-body open quantum systems. Within the continuum shell model, we...

Exact Solution of the Isovector Proton Neutron Pairing Hamiltonian (2006)

Dukelsky, J., Gueorguiev, V. G., Van Isacker, P., Dimitrova, S., Errea, B., H, S. Lerma

The complete exact solution of the T=1 neutron-proton pairing Hamiltonian is presented in the context of the SO(5) Richardson-Gaudin model with non-degenerate single-particle levels and including...

Density matrix renormalization group approach for many-body open quantum systems (2006)

Rotureau, J., Michel, N., Nazarewicz, W., Ploszajczak, M., Dukelsky, J.

The density matrix renormalization group (DMRG) approach is extended to complex-symmetric density matrices characteristic of many-body open quantum systems. Within the continuum shell model, we...

Exact Solution of the Isovector Proton Neutron Pairing Hamiltonian (2006)

Dukelsky, J., Gueorguiev, V. G., Van Isacker, P., Dimitrova, S., Errea, B., H, S. Lerma

The complete exact solution of the T=1 neutron-proton pairing Hamiltonian is presented in the context of the SO(5) Richardson-Gaudin model with non-degenerate single-particle levels and including...

Exactly-solvable models of proton and neutron interacting bosons (2006)

Lerma H., S., Errea, B., Dukelsky, J., Pittel, S., Van Isacker, P.

We describe a class of exactly-solvable models of interacting bosons based on the algebra SO(3,2). Each copy of the algebra represents a system of neutron and proton bosons in a given bosonic level...

Integrable models for asymmetric Fermi superfluids: Emergence of a new exotic pairing phase (2006)

DUKELSKY, J, ORTIZ, G, Rombouts, Stefan, Van Houcke, Kris

Integrable models for asymmetric Fermi superfluids: Emergence of a new exotic pairing phase (2005)

Dukelsky, J., Ortiz, G., Rombouts, S. M. A., Van Houcke, K.

We introduce an exactly-solvable model to study the competition between the Larkin-Ovchinnikov-Fulde-Ferrell (LOFF) and breached-pair superfluid in strongly interacting ultracold asymmetric Fermi...

Continuous unitary transformations in two-level boson systems (2005)

Dusuel, S., Vidal, J., Arias, J. M., Dukelsky, J., Garcia-Ramos, J. E.

Two-level boson systems displaying a quantum phase transition from a spherical (symmetric) to a deformed (broken) phase are studied. A formalism to diagonalize Hamiltonians with $O(2L+1)$ symmetry...

The $\beta^4$ potential at the U(5)-O(6) critical point of the Interacting Boson Model (2005)

Garcia-Ramos, J. E., Dukelsky, J., Arias, J. M.

Exact numerical results of the interacting boson model Hamiltonian along the integrable line from U(5) to O(6) are obtained by diagonalization within boson seniority subspaces. The matrix Hamiltonian...

Self-consistent random phase approximation: Application to the Hubbard model for finite number of sites (2005)

Jemai, M., Schuck, P., Dukelsky, J., Bennaceur, R.

Within the one-dimensional Hubbard model linear closed chains with various numbers of sites are considered in the self-consistent random phase approximation (SCRPA). Excellent results with a minimal...

Boson-Fermion pairing in a Boson-Fermion environment (2005)

Storozhenko, A., Schuck, P., Suzuki, T., Yabu, H., Dukelsky, J.

Propagation of a Boson-Fermion (B-F) pair in a B-F environment is considered. The possibility of formation of stable strongly correlated B-F pairs, embedded in the continuum, is pointed out. The new...

Finite-size scaling exponents in the interacting boson model (2005)

Dusuel, S., Vidal, J., Arias, J. M., Dukelsky, J., Garcia-Ramos, J. E.

We investigate the finite-size scaling exponents for the critical point at the shape phase transition from U(5) (spherical) to O(6) (deformed $\gamma$-unstable) dynamical symmetries of the...

Exactly-solvable models derived from a generalized Gaudin algebra (2005)

Ortiz, G, Somma, R, Dukelsky, J, Rombouts, S

We introduce a generalized Gaudin Lie algebra and a complete set of mutually commuting quantum invariants allowing the derivation of several families of exactly solvable Hamiltonians. Different...

Exactly-solvable models derived from a generalized Gaudin algebra (2005)

Somma, R, Dukelsky, J

We introduce a generalized Gaudin Lie algebra and a complete set of mutually commuting quantum invariants allowing the derivation of several families of exactly solvable Hamiltonians. Different...

Self-consistent random phase approximation: Application to the Hubbard model for finite number of sites (2005)

Jemai, M., Schuck, P., Dukelsky, J., Bennaceur, R.

Within the one-dimensional Hubbard model linear closed chains with various numbers of sites are considered in the self-consistent random phase approximation (SCRPA). Excellent results with a minimal...

Boson-Fermion pairing in a Boson-Fermion environment (2005)

Storozhenko, A., Schuck, P., Suzuki, T., Yabu, H., Dukelsky, J.

Propagation of a Boson-Fermion (B-F) pair in a B-F environment is considered. The possibility of formation of stable strongly correlated B-F pairs, embedded in the continuum, is pointed out. The new...

Self Consistent Random Phase Approximation and the restoration of symmetries within the three-level Lipkin model (2005)

Delion, D.S., Schuck, P., Dukelsky, J.

Self-consistent random phase approximation: Application to the Hubbard model for finite number of sites (2005)

Jemai, M., Schuck, P., Dukelsky, J., Bennaceur, R.

Within the one-dimensional Hubbard model linear closed chains with various numbers of sites are considered in the self-consistent random phase approximation (SCRPA). Excellent results with a minimal...

Boson-Fermion pairing in a Boson-Fermion environment (2005)

Storozhenko, A., Schuck, P., Suzuki, T., Yabu, H., Dukelsky, J.

Propagation of a Boson-Fermion (B-F) pair in a B-F environment is considered. The possibility of formation of stable strongly correlated B-F pairs, embedded in the continuum, is pointed out. The new...

Self Consistent Random Phase Approximation and the restoration of symmetries within the three-level Lipkin model (2005)

Delion, D.S., Schuck, P., Dukelsky, J.

Exactly-solvable models derived from a generalized Gaudin algebra (2005)

ORTIZ, G, SOMMA, R, DUKELSKY, J, Rombouts, Stefan

Phase Diagram of the Proton-Neutron Interacting Boson Model (2004)

Arias, J. M., Garcia-Ramos, J. E., Dukelsky, J.

We study the phase diagram of the proton--neutron interacting boson model (IBM--2) with special emphasis on the phase transitions leading to triaxial phases. The existence of a new critical point...

Exactly-Solvable Models Derived from a Generalized Gaudin Algebra (2004)

Ortiz, G., Somma, R., Dukelsky, J., Rombouts, S.

We introduce a generalized Gaudin Lie algebra and a complete set of mutually commuting quantum invariants allowing the derivation of several families of exactly solvable Hamiltonians. Different...

Exactly-solvable models for atom-molecule hamiltonians (2004)

Dukelsky, J., Dussel, G. G., Esebbag, C., Pittel, S.

We present a family of exactly-solvable generalizations of the Jaynes-Cummings model involving the interaction of an ensemble of SU(2) or SU(1,1) quasi-spins with a single boson field. They are...

Generalized Richardson-Gaudin Nuclear Models (2004)

Dukelsky, J., Gueorguiev, V. G., Van Isacker, P.

The exact solvability of several nuclear models with non-degenerate single-particle energies is outlined and leads to a generalization of integrable Richardson-Gaudin models, like the $su(2)$-based...

Solving the Richardson equations for fermions (2004)

Van Neck, D, Dukelsky, J

Forty years ago Richardson showed that the eigenstates of the pairing Hamiltonian with constant interaction strength can be calculated by solving a set of nonlinear coupled equations. However, in the...

Exactly solvable Richardson-Gaudin models for many-body quantum systems (2004)

Dukelsky, J., Pittel, S., Sierra, G.

The use of exactly-solvable Richardson-Gaudin (R-G) models to describe the physics of systems with strong pair correlations is reviewed. We begin with a brief discussion of Richardson's early work,...

Self Consistent Random Phase Approximation and the restoration of symmetries within the three-level Lipkin model (2004)

Delion, D. S., Schuck, P., Dukelsky, J.

We show that it is possible to restore the symmetry associated with the Goldstone mode within the Self Consistent Random Phase Approximation (SCRPA) applied to the three-level Lipkin model. We...

Bosons confined in optical lattices: The numerical renormalization group revisited (2004)

Pollet, L, Rombouts, S, Heyde, K, Dukelsky, J

A Bose-Hubbard model, describing bosons in a harmonic trap with a superimposed optical lattice, is studied using a fast and accurate variational technique (MF+NRG): the Gutzwiller mean-field (MF)...

Bosons confined in optical lattices: The numerical renormalization group revisited (2004)

Heyde, K, Dukelsky, J

A Bose-Hubbard model, describing bosons in a harmonic trap with a superimposed optical lattice, is studied using a fast and accurate variational technique (MF+NRG): the Gutzwiller mean-field (MF)...

Stringent Numerical Test of the Poisson Distribution for Finite Quantum Integrable Hamiltonians (2004)

Relano, A., Dukelsky, J., Gomez, J. M. G., Retamosa, J.

Using a new class of exactly solvable models based on the pairing interaction, we show that it is possible to construct integrable Hamiltonians with a Wigner distribution of nearest neighbor level...

Generalized Richardson-Gaudin Nuclear Models (2004)

Dukelsky, J., Gueorguiev, V.G., Van Isacker, P.

The exact solvability of several nuclear models with non-degenerate single-particle energies is outlined and leads to a generalization of integrable Richardson-Gaudin models, like the $su(2)$-based...

Solving the Richardson equations for fermions (2004)

Rombouts, Stefan, Van Neck, Dimitri, DUKELSKY, J

Bosons confined in optical lattices: The numerical renormalization group revisited (2004)

Pollet, Lode, Rombouts, Stefan, Heyde, Kristiaan, DUKELSKY, J

Entanglement in a first order quantum phase transition (2003)

Bosons Confined in Optical Lattices: the Numerical Renormalization Group revisited (2003)

The phase diagram of spins 1/2 embedded in a magnetic field mutually interacting antiferromagnetically is determined. Contrary to the ferromagnetic case where a second order quantum phase transition...

Pollet, L., Rombouts, S., Heyde, K., Dukelsky, J.

A Bose-Hubbard model, describing bosons in a harmonic trap with a superimposed optical lattice, is studied using a fast and accurate variational technique (MF+NRG): the Gutzwiller mean-field (MF)...

Integrability and Quantum Phase Transitions in Interacting Boson Models (2003)

Dukelsky, J., Arias, J. M., Garcia-Ramos, J. E., Pittel, S.

The exact solution of the boson pairing hamiltonian given by Richardson in the sixties is used to study the phenomena of level crossings and quantum phase transitions in the integrable regions of the...

Some new perspectives on pairing in nuclei (2003)

Pittel, S., Dukelsky, J.

Following a brief reminder of how the pairing model can be solved exactly, we describe how this can be used to address two interesting issues in nuclear structure physics. One concerns the mechanism...

Quantum Phase Transitions in the Interacting Boson Model: Integrability, level repulsion and level crossing (2003)

Arias, J. M., Dukelsky, J., Garcia-Ramos, J. E.

We study the quantum phase transition mechanisms that arise in the Interacting Boson Model. We show that the second-order nature of the phase transition from U(5) to O(6) may be attributed to quantum...

The U(5)-O(6) transition in the Interacting Boson Model and the E(5) critical point symmetry (2003)

Arias, J. M., Alonso, C. E., Vitturi, A., Garcia-Ramos, J. E., Dukelsky, J., Frank, A.

The relation of the recently proposed E(5) critical point symmetry with the interacting boson model is investigated. The large-N limit of the interacting boson model at the critical point in the...

Comment on ``Polynomial-Time Simulation of Pairing Models on a Quantum Computer'' (2003)

Dukelsky, J., Roman, J. M., Sierra, G.

Comment on the Letter ``Polynomial-Time Simulation of Pairing Models on a Quantum Computer'', L. A. Wu, M. S. Byrd and D. A. Lidar, Phys. Rev. Lett. 89, 057904 (2002).

Pair Fluctuations in Ultra-small Fermi Systems within Self-Consistent RPA at Finite Temperature (2003)

Storozhenko, A., Schuck, P., Dukelsky, J., Röpke, G., Vdovin, A.

A self-consistent version of the Thermal Random Phase Approximation (TSCRPA) is developed within the Matsubara Green's Function (GF) formalism. The TSCRPA is applied to the many level pairing model....

The Density Matrix Renormalization Group in Nuclear Physics: A Status Report (2003)

Pittel, S., Dukelsky, J., Dimitrova, S., Stoitsov, M.

We report on the current status of recent efforts to develop the Density Matrix Renormalization Group method for use in large-scale nuclear shell-model calculations.

The elementary excitations of the BCS model in the canonical ensemble (2003)

Sierra, G., Roman, J. M., Dukelsky, J.

We summarize previous works on the exact ground state and the elementary excitations of the exactly solvable BCS model in the canonical ensemble. The BCS model is solved by Richardson equations, and,...

Entanglement in a first order quantum phase transition (2003)

Pair Fluctuations in Ultra-small Fermi Systems within Self-Consistent RPA at Finite Temperature (2003)

The phase diagram of spins 1/2 embedded in a magnetic field mutually interacting antiferromagnetically is determined. Contrary to the ferromagnetic case where a second order quantum phase transition...

Storozhenko, A., Schuck, P., Dukelsky, J., Roepke, G., Vdovin, A.

Comparison between exact and approximate treatments of the pairing interaction for finite Fermi systems (2003)

Dukelsky, J., Dussel, G.G., Hirsch, J.G., Schuck, P.

Pair Fluctuations in Ultra-small Fermi Systems within Self-Consistent RPA at Finite Temperature (2003)

Storozhenko, A., Schuck, P., Dukelsky, J., Roepke, G., Vdovin, A.

Comparison between exact and approximate treatments of the pairing interaction for finite Fermi systems (2003)

Dukelsky, J., Dussel, G.G., Hirsch, J.G., Schuck, P.

Entanglement in a first order quantum phase transition (2003)

What are the elementary excitations of the BCS model in the canonical ensemble? (2002)

The phase diagram of spins 1/2 embedded in a magnetic field mutually interacting antiferromagnetically is determined. Contrary to the ferromagnetic case where a second order quantum phase transition...

Roman, J. M., Sierra, G., Dukelsky, J.

We have found the elementary excitations of the exactly solvable BCS model for a fixed number of particles. These turn out to have a peculiar dispersion relation, some of them with no counterpart in...

The Density Matrix Renormalization Group Method for Realistic Large-Scale Nuclear Shell-Model Calculations (2002)

Dimitrova, S. S., Pittel, S., Dukelsky, J., Stoitsov, M. V.

The Density Matrix Renormalization Group (DMRG) method is developed for application to realistic nuclear systems. Test results are reported for 24Mg.

The Pairing interaction in nuclei: comparison between exact and approximate treatments (2002)

Dukelsky, J., Dussel, G. G., Hirsch, J. G., Schuck, P.

As a model for a deformed nucleus the many level pairing model (picket fence model with ~100 levels) is considered in four approximations and compared to the exact solution given by Richardson long...

Condensate fragmentation in a new exactly solvable model for confined bosons (2002)

The Density Matrix Renormalization Group Method and Large-Scale Nuclear Shell-Model Calculations (2002)

Dukelsky, J., Pittel, S., Dimitrova, S. S., Stoitsov, M. V.

The particle-hole Density Matrix Renormalization Group (p-h DMRG) method is discussed as a possible new approach to large-scale nuclear shell-model calculations. Following a general description of...

Large N limit of the exactly solvable BCS model: analytics versus numerics (2002)

Roman, J. M., Sierra, G., Dukelsky, J.

We have studied the numerical solutions of Richardson equations of the BCS model in the limit of large number of energy levels at half-filling, and compare them with the analytic results derived by...

Fully self-consistent RPA description of the many level pairing model (2002)

Hirsch, J.G., Mariano, A., Dukelsky, J., Schuck, P.

The self-consistent RPA (SCRPA) equations in the particle-particle channel are solved without any approximation for the picket fence model. The results are in excellent agreement with the exact...

Fully self-consistent RPA description of the many level pairing model (2002)

Hirsch, J.G., Mariano, A., Dukelsky, J., Schuck, P.

The self-consistent RPA (SCRPA) equations in the particle-particle channel are solved without any approximation for the picket fence model. The results are in excellent agreement with the exact...

Electrostatic mapping of nuclear pairing (2001)

Dukelsky, J., Esebbag, C., Pittel, S.

The traditional nuclear pairing problem is shown to be in one-to-one correspondence with a classical electrostatic problem in two dimensions. We make use of this analogy in a series of calculations...

Class of exactly solvable pairing models (2001)

A Class of Exactly Solvable Pairing Models (2001)

Restoration of broken symmetries in Self-Consistent RPA (2001)

We present three classes of exactly solvable models for fermion and boson systems, based on the pairing interaction. These models are solvable in any dimension. As an example we show the first...

Rabhi, A., Schuck, P., Bennaceur, R., Chanfray, G., Dukelsky, J.

Restoration of broken symmetries in Self-Consistent RPA (2001)

Rabhi, A., Schuck, P., Bennaceur, R., Chanfray, G., Dukelsky, J.

It is shown that the Self-Consistent RPA (SCRPA) approach allows in a very natural way to restore symmetries, spontaneously broken on the mean field level. This is achieved via the introduction of a...

Restoration of broken symmetries in Self-Consistent RPA (2001)

Rabhi, A., Schuck, P., Bennaceur, R., Chanfray, G., Dukelsky, J.

Restoration of broken symmetries in Self-Consistent RPA (2001)

Rabhi, A., Schuck, P., Bennaceur, R., Chanfray, G., Dukelsky, J.

New mechanism for the enhancement of $sd$ dominance in interacting boson models (2001)

Dukelsky, J., Pittel, S.

We introduce an exactly solvable model for interacting bosons that extend up to high spin and interact through a repulsive pairing force. The model exhibits a phase transition to a state with almost...

A New Approach to Large-Scale Nuclear Structure Calculations (2001)

Dukelsky, J., Pittel, S.

A new approach to large-scale nuclear structure calculations, based on the Density Matrix Renormalization Group (DMRG), is described. The method is tested in the context of a problem involving many...

Condensate fragmentation in a new exactly solvable model for confined bosons (2001)

Class of exactly solvable pairing models (2001)

Restoration of broken symmetries in Self-Consistent RPA (2001)

Rabhi, A., Schuck, P., Bennaceur, R., Chanfray, G., Dukelsky, J.

Self-consistent random phase approximation in a schematic field theoretical model (2001)

Bertrand, T., Schuck, P., Chanfray, G., Aouissat, Z., Dukelsky, J.

Condensate fragmentation in a new exactly solvable model for confined bosons (2001)

Class of exactly solvable pairing models (2001)

Restoration of broken symmetries in Self-Consistent RPA (2001)

Rabhi, A., Schuck, P., Bennaceur, R., Chanfray, G., Dukelsky, J.

Self-consistent random phase approximation in a schematic field theoretical model (2001)

Bertrand, T., Schuck, P., Chanfray, G., Aouissat, Z., Dukelsky, J.

Class of Exactly Solvable Pairing Models (2001)

New Mechanism for the Enhancement of sd Dominance in Interacting Boson Models (2001)

Dukelsky, J., Pittel, S.

Condensate Fragmentation in a New Exactly Solvable Model for Confined Bosons (2001)

Condensate Fragmentation in a New Exactly Solvable Model for Confined Bosons (2000)

Intrinsic state for an extended version of the interacting boson model (2000)

Based on Richardson's exact solution of the pairing model and the Gaudin model for spin systems we derive a new class of exactly solvable models for finite boson system. As an example we solve a...

Garcia-Ramos, J.E., Arias, J.M., Dukelsky, J., Van Isacker, P.

Proton-neutron self-consistent quasiparticle random phase approximation within the O(5) model (2000)

Delion, D.S., Dukelsky, J., Schuck, P., Krmpotic, F.

Occupation numbers in self consistent RPA (2000)

Intrinsic state for an extended version of the interacting boson model (2000)

A method is proposed which allows to calculate within the SCRPA theory the occupation numbers via the single particle Green function. This scheme complies with the Hugenholtz van Hove theorem. In an...

Garcia-Ramos, J.E., Arias, J.M., Dukelsky, J., Van Isacker, P.

Proton-neutron self-consistent quasiparticle random phase approximation within the O(5) model (2000)

Delion, D.S., Dukelsky, J., Schuck, P., Krmpotic, F.

Occupation numbers in self consistent RPA (2000)

Exact Study of the Effect of Level Statistics in Ultrasmall Superconducting Grains (1999)

A method is proposed which allows to calculate within the SCRPA theory the occupation numbers via the single particle Green function. This scheme complies with the Hugenholtz van Hove theorem. In an...

Sierra, G., Dukelsky, J., Dussel, G. G., Von Delft, Jan, Braun, Fabian

The reduced BCS model that is commonly used for ultrasmall superconducting grains has an exact solution worked out long ago by Richardson in the context of nuclear physics. We use it to check the...

An intrinsic state for an extended version of the interacting boson model (1999)

Garcia-Ramos, J. E., Arias, J. M., Dukelsky, J., Van Isacker, P.

An intrinsic-state formalism for IBM-4 is presented. A basis of deformed bosons is introduced which allows the construction of a general trial wave function which has Wigner's spin-isospin SU(4)...

The Crossover from the Bulk to the Few-Electron limit in Ultrasmall Metallic Grains (1999)

Dukelsky, J., Sierra, G.

We study the properties of ultrasmall metallic grains with sizes in the range of 20 up to 400 electrons. Using a particle-hole version of the DMRG method we compute condensation energies,...

Occupation numbers in Self Consistent RPA (1999)

Dukelsky, J., Hirsch, J. G., Schuck, P.

A method is proposed which allows to calculate within the SCRPA theory the occupation numbers via the single particle Green function. This scheme complies with the Hugenholtz van Hove theorem. In an...

A Density Matrix Renormalization Group Study of Ultrasmall Superconducting Grains (1999)

Dukelsky, J., Sierra, G.

We apply the DMRG method to the BCS pairing Hamiltonian which describes ultrasmall superconducting grains. Our version of the DMRG uses the particle (hole) states around the Fermi level as the system...

The self consistent RPA in a many level pairing model (1999)

The self consistent RPA in a many level pairing model (1999)

Phase Diagram of the 2-Leg Heisenberg Ladder with Alternating Dimerization (1998)

Martin-Delgado, M. A., Dukelsky, J., Sierra, G.

Using the Lanczos method we determine the phase diagram of the 2-leg AF-Heisenberg ladder with alternating dimerization. It consists of a resonating valence bond phase and a dimer phase separated by...

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...

Self consistent random phase approximation within the O(5) model and Fermi transitions (1998)

Krmpotic, F., Delion, D. S., Dukelsky, J., Schuck, P.

Self Consistent Quasiparticle Random Phase Approximation (SCQRPA) is considered in application to the Fermi transitions within the O(5) model. It is demonstrated that SCQRPA improves on renormalized...

The Matrix Product Approach to Quantum Spin Ladders (1998)

Roman, J. M., Sierra, G., Dukelsky, J., Martin-Delgado, M. A.

We present a manifestly rotational invariant formulation of the matrix product method valid for spin chains and ladders. We apply it to 2 legged spin ladders with spins 1/2, 1 and 3/2 and different...

The self consistent RPA (1998)

The Dyson equation approach to many body Green's functions (1998)

Generalized Brueckner-Hartree-Fock theory and self-consistent RPA (1998)

Dukelsky, J., Roepke, G., Schuck, P.

Self-consistent random phase approximation within the O(5) model and Fermi transitions (1998)

Krmpotic, F., Delion, D.S., Dukelsky, J., Schuck, P.

Self Consistent Quasiparticle Random Phase Approximation (SCQRPA) is considered in application to the Fermi transitions within the O(5) model. It is demonstrated that SCQRPA improves on renormalized...

The self consistent RPA (1998)

The Dyson equation approach to many body Green's functions (1998)

Generalized Brueckner-Hartree-Fock theory and self-consistent RPA (1998)

Dukelsky, J., Roepke, G., Schuck, P.

Self-consistent random phase approximation within the O(5) model and Fermi transitions (1998)

Krmpotic, F., Delion, D.S., Dukelsky, J., Schuck, P.

Self Consistent Quasiparticle Random Phase Approximation (SCQRPA) is considered in application to the Fermi transitions within the O(5) model. It is demonstrated that SCQRPA improves on renormalized...

Equivalence of the Variational Matrix Product Method and the Density Matrix Renormalization Group applied to Spin Chains (1997)

Dukelsky, J., Martin-Delgado, M. A., Nishino, T., Sierra, G.

We present a rotationally invariant matrix product method (MPM) of isotropic spin chains. This allows us to deal with a larger number of variational MPM parameters than those considered earlier by...

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...

A Hartree-Bose Mean-Field Approximation for IBM-3 (1997)

Garcia-Ramos, J. E., Arias, J. M., Dukelsky, J., De Guerra, E. Moya, Van Isacker, P.

A Hartree-Bose mean-field approximation for the IBM-3 is presented. A Hartree- Bose transformation from spherical to deformed bosons with charge-dependent parameters is proposed which allows bosonic...

Neutron-proton correlations in an exactly solvable model (1997)

Engel, J., Pittel, S., Stoitsov, M., Vogel, P., Dukelsky, J.

We examine isovector and isoscalar neutron-proton correlations in an exactly solvable model based on the algebra SO(8). We look particularly closely at Gamow-Teller strength and double β decay, both...

Fermion condensation and non Fermi liquid behavior in a model with long range forces (1997)

Dukelsky, J., Khodel, V.A., Schuck, P., Shaginyan, V.R.

Restoration of the Ikeda sum rule in self-consistent quasiparticle random-phase approximation (1997)

Delion, D.S., Dukelsky, J., Schuck, P.

Description of deuteron and $\alpha$-particle condensation in nuclear matter (1997)

Fermion condensation and non Fermi liquid behavior in a model with long range forces (1997)

Dukelsky, J., Khodel, V.A., Schuck, P., Shaginyan, V.R.

Restoration of the Ikeda sum rule in self-consistent quasiparticle random-phase approximation (1997)

Delion, D.S., Dukelsky, J., Schuck, P.

Description of deuteron and $\alpha$-particle condensation in nuclear matter (1997)

Neutron-Proton Correlations in an Exactly Solvable Model (1996)

Engel, J., Pittel, S., Vogel, P., Stoitsov, M., Dukelsky, J.

We examine isovector and isoscalar neutron-proton correlations in an exactly solvable model based on the algebra SO(8). We look particularly closely at Gamow-Teller strength and double beta decay,...

Fermion Condensation and Non Fermi Liquid Behavior in a Model with Long Range Forces (1996)

Dukelsky, J., Khodel, V. A., Schuck, P., Shaginyan, V. R.

The phenomenon of the so called Fermion condensation, a phase transition analogous to Bose condensation but for Fermions, postulated in the past to occur in systems with strong momentum dependent...

Self consistent RPA for superfluid Fermi systems (1996)

Deuteron formation in expanding nuclear matter from a strong coupling BCS approach (1996)

Baldo, M., Dukelsky, J., Gulminelli, F., Lombardo, U., Schuck, P.

Self consistent RPA for superfluid Fermi systems (1996)

Deuteron formation in expanding nuclear matter from a strong coupling BCS approach (1996)

Baldo, M., Dukelsky, J., Gulminelli, F., Lombardo, U., Schuck, P.

Deuteron formation in expanding nuclear matter from a strong coupling BCS approach (1995)

Baldo, Marcello, Dukelsky, J, Gulminelli, F, Lombardo, U, Schuck, P

Variational random phase approximation for the anharmonic oscillator (1991)