Información del autor
Autor Pérez García, David |
Documentos disponibles escritos por este autor (74)
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Lucia, Ángelo ; Cubitt, Toby S. ; Michalakis, Spyridon ; Pérez García, David | American Physical Society | 2014-09-27The physics of many materials is modeled by quantum many-body systems with local interactions. If the model of the system is sensitive to noise from the environment, or small perturbations to the original interactions, it will not model properly[...]texto impreso
Schuch, Norbert ; Poilblanc, Didier ; Cirac, Juan I. ; Pérez García, David | American Physical Society | 2012-09We study resonating valence bond (RVB) states in the projected entangled pair states (PEPS) formalism. Based on symmetries in the PEPS description, we establish relations between the toric code state, the orthogonal dimer state, and the SU(2) si[...]texto impreso
Cirac, J. Ignacio ; Michalakis, Spyridon ; Pérez García, David ; Schuch, Norbert | American Physical Society | 2013-09-06We analyze a criterion which guarantees that the ground states of certain many-body systems are stable under perturbations. Specifically, we consider PEPS, which are believed to provide an efficient description, based on local tensors, for the l[...]texto impreso
Iblisdir, I. ; Pérez García, David ; Aguado, M. ; Pachos, J. | American Physical Society | 2009-04-16Understanding the behavior of topologically ordered lattice systems at finite temperature is a way of assessing their potential as fault-tolerant quantum memories. We compute the natural extension of the topological entanglement entropy for T> 0[...]texto impreso
Lamata, L. ; León, J. ; Pérez García, David ; Salgado, D. ; Solano, E. | American Physical Society | 2008-10-31We study the possibility for a global unitary applied on an arbitrary number of qubits to be decomposed in a sequential unitary procedure, where an ancillary system is allowed to interact only once with each qubit. We prove that sequential unita[...]texto impreso
We study scenarios where a finite set of non-demolition von-Neumann measurements are available. We note that, in some situations, repeated application of such measurements allows estimating an infinite number of parameters of the initial quantum[...]texto impreso
Bañuls, M.C. ; Pérez García, David ; Wolf, M.M. ; Verstraete, F. ; Cirac, J.I. | American Physical Society | 2008Matrix product states can be defined as the family of quantum states that can be sequentially generated in a one-dimensional system [Schon et al., Phys. Rev. Lett. 95, 110503 (2005)]. We introduce a family of states that extends this definition [...]texto impreso
Cubitt, Toby S. ; Lucia, Ángelo ; Michalakis, Spyridon ; Pérez García, David | Springer | 2015-08-29Open quantum systems weakly coupled to the environment are modeled by completely positive, trace preserving semigroups of linear maps. The generators of such evolutions are called Lindbladians. In the setting of quantum many-body systems on a la[...]texto impreso
Pérez García, David ; Wolf, M.M. ; Sanz, M. ; Verstraete, F. ; Cirac, J.I. | The American Physical Society | 2008-04-25We show that the existence of string order in a given quantum state is intimately related to the presence of a local symmetry by proving that both concepts are equivalent within the framework of finitely correlated states. Once this connection i[...]texto impreso
This is the supplementary information associated to the article: T.S. Cubitt, D. Perez-Garcia, M.M. Wolf, Undecidability of the spectral gap, Nature 528, 207-211 (2015), doi:10.1038/nature16059texto impreso
Topological ordered phases are related to changes in the properties of their quasiparticle excitations (anyons). We study these relations in the framework of projected entanglement pair states and show how condensing and confining anyons reduces[...]texto impreso
What can we say about the spectra of a collection of microscopic variables when only their coarse-grained sums are experimentally accessible? In this paper, using the tools and methodology from the study of quantum nonlocality, we develop a math[...]texto impreso
Wolf, Michael ; Pérez García, David | 2010Given a list of n complex numbers, when can it be the spectrum of a quantum channel, i.e., a completely positive trace preserving map? We provide an explicit solution for the n=4 case and show that in general the characterization of the non-zero[...]texto impreso
We prove that the only rearrangement invariant (r.i.) spaces for which there exists a crossnorm verifying that the tensor product of these spaces preserves the "natural" r.i. space structure, in the sense that it makes the multiplication operato[...]texto impreso
A study of the thermal properties of two-dimensional topological lattice models is presented. This work is relevant to assess the usefulness of these systems as a quantum memory. For our purposes, we use the topological mutual information I(topo[...]texto impreso
Poilblanc, Didier ; Schuch, Norbert ; Pérez García, David ; Cirac, J. Ignacio | American Physical Society | 2012-07-06We examine in details the connections between topological and entanglement properties of short-range resonating valence bond (RVB) wave functions using projected entangled pair states (PEPS) on kagome and square lattices on (quasi)infinite cylin[...]texto impreso
Schuch, Norbert ; Poilblanc, Didier ; Cirac, J.I. ; Pérez García, David | American Physical Society | 2013We study the structure of topological phases and their boundaries in the projected entangled-pair states (PEPS) formalism. We show how topological order in a system can be identified from the structure of the PEPS transfer operator and subsequen[...]texto impreso
Villanueva, Ignacio ; Junge, Marius ; Pérez García, David ; Wolf, Michael ; Palazuelos Cabezón, Carlos | Springer | 2008We prove that there are tripartite quantum states (constructed from random unitaries) that can lead to arbitrarily large violations of Bell inequalities for dichotomic observables. As a consequence these states can withstand an arbitrary amount [...]texto impreso
Villanueva, Ignacio ; Junge, Marius ; Pérez García, David ; Wolf, Michael ; Palazuelos Cabezón, Carlos | Springer | 2010-12In this work we show that bipartite quantum states with local Hilbert space dimension n can violate a Bell inequality by a factor of order ?(?n?Log2n) when observables with n possible outcomes are used. A central tool in the analysis is a close[...]texto impreso
Junge, M. ; Pérez García, David ; Palazuelos Cabezón, Carlos ; Villanueva, Ignacio ; Wolf, Michael | Springer | 2010In this work we show that bipartite quantum states with local Hilbert space dimension n can violate a Bell inequality by a factor of order $\sqrt{n}$ (up to a logarithmic factor) when observables with n possible outcomes are used. A central tool[...]texto impreso
Villanueva, Ignacio ; Pérez García, David | Matematisk Institut, Universitetsparken NY Munkegade | 2005We prove that a tensor norm alpha (defined on tensor products of Hilbert spaces) is the Hilbert-Schmidt norm if and only if l(2) circle times(...)circle times l(2), endowed with the norm alpha, has an unconditional basis. This extends a classica[...]texto impreso
The spectral gap-the energy difference between the ground state and first excited state of a system-is central to quantum many-body physics. Many challenging open problems, such as the Haldane conjecture, the question of the existence of gapped [...]texto impreso
Villanueva, Ignacio ; Pérez García, David ; Cabello Sánchez, Félix | Oxford University Press | 2006-10We describe complemented Copies Of l(2) both in C(K-1)circle times C-pi(K-2) when at least one of the compact spaces K-i is not scattered and in L-1(mu(1))circle times L-is an element of(1)(mu(2)) when at least one of the measures is not atomic.[...]texto impreso
Using a ‘reasonable’ measure in , the space of 2-homogeneous polynomials on ?1n, we show the existence of a set of positive (and independent of n) measure of polynomials which do not attain their norm at the vertices of the unit ball of ?1n. Ne[...]