173 citations · 367 across the 13 of their papers we have counts for
8 papers · 1 filter
Twisted Order Parameter applied to Dimerized Ladders
J. Almeida, M. A. Martin-Delgado, G. Sierra
We apply the twisted order parameter (TOP) for dimerized quantum spin ladders to locate the critical phases that separate gapped phases representing quantum spin liquids of various…
Critical Lines and Massive Phases in Quantum Spin Ladders with Dimerization
Javier Almeida, M. A. Martin-Delgado, G. Sierra
We determine the existence of critical lines in dimerized quantum spin ladders in their phase diagram of coupling constants using the finite-size DMRG algorithm. We consider both s…
Stripe Ansatzs from Exactly Solved Models
M. A. Martin-Delgado, M. Roncaglia, G. Sierra
Using the Boltzmann weights of classical Statistical Mechanics vertex models we define a new class of Tensor Product Ansatzs for 2D quantum lattice systems, characterized by a stro…
Matrix Product Approach to Conjugated Polymers
M. A. Martin-Delgado, G. Sierra, S. Pleutin +1
The Matrix Product method (MPM) has been used in the past to generate variational ansatzs of the ground state (GS) of spin chains and ladders. In this paper we apply the MPM to stu…
The dimer-RVB State of the Four-Leg Heisenberg Ladder: Interference among Resonances
M. Roncaglia, G. Sierra, M. A. Martin-Delgado
We study the ground state of the 4-leg spin ladder using a dimer-RVB ansatz and the Lanczos method. Besides the well known resonance mechanism between valence bond configurations w…
The Density Matrix Renormalization Group applied to single-particle Quantum Mechanics
M. A. Martin-Delgado, G. Sierra, R. M. Noack
A simplified version of White's Density Matrix Renormalization Group (DMRG) algorithm has been used to find the ground state of the free particle on a tight-binding lattice. We gen…
Phase Diagram of the 2-Leg Heisenberg Ladder with Alternating Dimerization
M. A. Martin-Delgado, J. Dukelsky, G. Sierra
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…
Equivalence of the Variational Matrix Product Method and the Density Matrix Renormalization Group applied to Spin Chains
J. Dukelsky, M. A. Martin-Delgado, T. Nishino +1
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 consi…