Información del autor
Autor Relaño Pérez, Armando |
Documentos disponibles escritos por este autor (48)
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Relaño Pérez, Armando ; Retamosa Granado, Joaquín ; Faleiro, E. ; Molina, R. A. ; Zuker, A. P. | American Physical Society | 2006-02It was recently pointed out that the spectral fluctuations of quantum systems are formally analogous to discrete time series, and therefore their structure can be characterized by the power spectrum of the signal. Moreover, it is found that the [...]texto impreso
Relaño Pérez, Armando ; Molina, R. A. ; Retamosa Granado, Joaquín | American Physical Society | 2004-07We show that the spectral fluctuations of the two-body random ensemble exhibit 1/f noise. This result supports a recent conjecture stating that chaotic quantum systems are characterized by 1/f noise in their energy level fluctuations. After suit[...]texto impreso
Relaño Pérez, Armando ; Gómez Gómez, José María ; Retamosa Granado, Joaquín ; Faleiro, E. ; Salasnich, L. ; Vranicar, M. ; Robnik, M. | American Physical Society | 2005-03-04The power law 1/ƒ^(?) in the power spectrum characterizes the fluctuating observables of many complex natural systems. Considering the energy levels of a quantum system as a discrete time series where the energy plays the role of time, the level[...]texto impreso
Bastarrachea Magnani A.; R, M. A. ; Relaño Pérez, Armando ; Lerma Hernández, S. ; López del Carpio, B. ; Chávez Carlos, J. ; Hirsch, J. G. | IOP publishing ltd | 2017-04-07Adiabatic invariants for the non-integrable Dicke model are introduced. They are shown to provide approximate second integrals of motion in the energy region where the system exhibits a regular dynamics. This low-energy region, present for any s[...]texto impreso
Pérez Fernández, P. ; Relaño Pérez, Armando ; Dukelsky, J. ; Arias, J. M. | American Institute of Physics (AIP) | 2013The Bose-Hubbard model coupled to a Feshbach resonance is studied. Quantum phase transitions are analyzed within a beyond mean field framework in order to get finite size corrections to the simple mean field approach. Analytical results for the [...]texto impreso
Gómez, J. M. G. ; Faleiro, E. ; Molina, R. A. ; Muñoz, L. ; Relaño Pérez, Armando | World Scientific Publishing Company | 2005-03Many complex systems in nature and in human society exhibit time fluctuations characterized by a power spectrum S(f) which is a power function of the frequency f . Examples with this behavior are the Sun spot activity, the human heartbeat, the D[...]texto impreso
It has been shown that the spectral fluctuations of different quantum systems are characterized by 1/ƒ^(?) noise, with 1texto impreso
Muñoz, Laura ; Fernández Ramírez, César ; Relaño Pérez, Armando ; Retamosa Granado, Joaquín | IOP publishing ltd | 2012In the last decade quantum chaos has become a well established discipline with outreach to different fields, from condensed-matter to nuclear physics. The most important signature of quantum chaos is the statistical analysis of the energy spectr[...]texto impreso
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Pérez Fernández, P. ; Relaño Pérez, Armando ; Arias, J. M. ; Dukelsky, J. ; García Ramos, J. E. | American Institute of Physics (AIP) | 2010In this work we explore the relationship between an excited state quantum phase transition (ESQPT) and the phenomenon of quantum decoherence. For this purpose, we study how the decoherence is affected by the presence of a continuous ESQPT in the[...]texto impreso
Relaño Pérez, Armando ; Retamosa Granado, Joaquín ; Faleiro, E. ; Gómez Gómez, José María | American Physical Society | 2005-12The existence of a formal analogy between quantum energy spectra and discrete time series has been recently pointed out. When the energy level fluctuations are described by means of the ?_(n) statistic, it is found that chaotic quantum systems a[...]texto impreso
García Ramos, J. E. ; Arias, J. M. ; Cejnar, P. ; Dukelsky, J. ; Pérez Fernández, P. ; Relaño Pérez, Armando | American Institute of Physics (AIP) | 2012We study the similarities and differences between the phenomena of Quantum Decoherence and Quantum Quench in presence of an Excited State Quantum Phase Transition (ESQPT). We analyze, on one hand, the decoherence induced on a single qubit by the[...]texto impreso
Relaño Pérez, Armando ; Arias, J. M. ; Dukelsky, J. ; García Ramos, J. E. ; Pérez Fernández, P. | American Physical Society | 2008-12We analyze the decoherence induced on a single qubit by the interaction with a two-level boson system with critical internal dynamics. We explore how the decoherence process is affected by the presence of quantum phase transitions in the environ[...]texto impreso
García Ramos, J. E. ; Arias, J. M. ; Dukelsky, J. ; Pérez Fernández, P. ; Relaño Pérez, Armando | American Institute of Physics (AIP) | 2009We analyze the decoherence induced on a single qubit by the interaction with a two-level boson system with critical internal dynamics. We explore how the decoherence process is affected by the presence of quantum phase transitions in the environ[...]texto impreso
Relaño Pérez, Armando ; Pérez Fernández, P. ; Arias, J. M. ; Dukelsky, J. ; García Ramos, J. E. | American Physical Society | 2009-09The decoherence induced on a single qubit by its interaction with the environment is studied. The environment is modeled as a scalar two-level boson system that can go through either first-order or continuous-excited-state quantum phase transiti[...]texto impreso
The decoherence interpretation of quantum measurements is applied to Wigner's-friend experiments. A framework in which all the experimental outcomes arise from unitary evolutions is proposed. Within it, a measurement is not completed until an un[...]texto impreso
Decoherence induced by an interacting spin environment in the transition from integrability to chaos
We investigate the decoherence properties of a central system composed of two spins 1/2 in contact with a spin bath. The dynamical regime of the bath ranges from a fully integrable limit to complete chaoticity. We show that the dynamical regime [...]texto impreso
Theoretical expressions for the distribution of the ratio of consecutive level spacings for quantum systems with transiting dynamics remain unknown. We propose a family of one-parameter distributions P(r) P(r; beta), where beta is an element of [...]texto impreso
We study nonequilibrium processes in an isolated quantum system-the Dicke model-focusing on the role played by the transition from integrability to chaos and the presence of excited-state quantum phase transitions. We show that both diagonal and[...]texto impreso
Pérez Fernández, P. ; Relaño Pérez, Armando ; Arias, J. M. ; Cejnar, P. ; Dukelsky, J. ; García Ramos, J. E. | American Physical Society | 2011-04-15We study the critical behavior of excited states and its relation to order and chaos in the Jaynes-Cummings and Dicke models of quantum optics. We show that both models exhibit a chain of excited-state quantum phase transitions demarcating the u[...]texto impreso
Puebla, Ricardo ; Relaño Pérez, Armando ; Retamosa Granado, Joaquín | American Physical Society | 2013-02-19We study the phase diagram of the Dicke model in terms of the excitation energy and the radiation-matter coupling constant lambda. Below a certain critical value lambda(c), all the energy levels have a well-defined parity. For lambda > lambda(c[...]texto impreso
Pérez Fernández, P. ; Relaño Pérez, Armando ; Cejnar, P. ; Arias, J. M. ; Dukelsky, J. ; García Ramos, J. E. | American Institute of Physics (AIP) | 2012In this contribution, the critical behavior of excited state quantum phase transitions (ESQPT's) and its relation to order and chaos in the Dicke model are studied. This model is non-integrable. For comparison, the same problem is studied for th[...]texto impreso
We study the integrability of the two-spin elliptic Gaudin model for arbitrary values of the Hamiltonian parameters. The limit of a very large spin coupled to a small one is well described by a semiclassical approximation with just one degree of[...]texto impreso
We present a theory that accurately describes the counting of excited states of a noninteracting fermionic gas. At high excitation energies the results reproduce Bethe's theory. At low energies oscillatory corrections to the many-body density of[...]texto impreso
We study the thermodynamics of the full version of the Dicke model, including all the possible values of the total angular momentum j, with bothmicrocanonical and canonical ensembles. We focus on both the excited-state quantum phase transition, [...]texto impreso
For a certain class of isolated quantum systems, we report the existence of irreversible processes in which the energy is not dissipated. After a closed cycle in which the initial energy distribution is fully recovered, the expectation value of [...]texto impreso
Gómez Gómez, José María ; Molina, R. A. ; Relaño Pérez, Armando ; Retamosa Granado, Joaquín | American Physical Society | 2002-09The main signature of chaos in a quantum system is provided by spectral statistical analysis of the nearest-neighbor spacing distribution P(s) and the spectral rigidity given by the Delta(3)(L) statistic. It is shown that some standard unfolding[...]texto impreso
Pachón, Leonardo A. ; Relaño Pérez, Armando ; Peropadre, Borja ; Aspuru-Guzik, Alán | Amer Physical Soc | 2018-10-19Based on the connection between the spectral form factor and the probability to return, the origin of the energy level fluctuation 1/f(alpha) noise in fully chaotic and fully integrable systems is traced to the quantum interference between invar[...]texto impreso
Relaño Pérez, Armando ; Molina, R. A. ; Retamosa Granado, Joaquín ; Muñoz, L. ; Faleiro, E. ; Gómez Gómez, José María | IOP publishing ltd | 2010The power spectrum of the ?_(n) statistic of quantum spectra presents 1/ƒ^(?) noise. For chaotic systems ? = 1 while for regular systems ? = 2. Although the transition from regularity to chaos is non universal, for a wide variety of systems wi[...]texto impreso
Relaño Pérez, Armando ; Muñoz, L. ; Retamosa Granado, Joaquín ; Faleiro, E. ; Molina, R. A. | American Physical Society | 2008-03The continuous Gaussian ensemble, also known as the nu-Gaussian or nu-Hermite ensemble, is a natural extension of the classical Gaussian ensembles of real (nu= 1), complex (nu= 2), or quaternion (nu=4) matrices, where nu is allowed to take any p[...]texto impreso
Relaño Pérez, Armando ; Molina, R. A. ; Retamosa Granado, Joaquín ; Muñoz, L. ; Faleiro, E. | Elsevier Science BV | 2007-01-04Sequences of energy levels in nuclei are often plagued with missing levels whose number and position are unknown. It is also quite usual that all the quantum numbers of certain levels cannot be experimentally determined, and thus levels of diffe[...]texto impreso
Faleiro, E. ; Gómez Gómez, José María ; Muñoz, L. ; Relaño Pérez, Armando ; Retamosa Granado, Joaquín | University Chicago Press | 2004-11We apply a principal components analysis (PCA) to the secondary particle density distributions at ground level produced by cosmic gamma-rays and protons. For this purpose, high-energy interactions of cosmic rays with Earth's atmosphere and the r[...]texto impreso
Relaño Pérez, Armando ; Gómez Gómez, José María ; Molina, R. A. ; Retamosa Granado, Joaquín ; Faleiro, E. | American Physical Society | 2002-12-09The main signature of chaos in a quantum system is provided by spectral statistical analysis of the nearest-neighbor spacing distribution P(s) and the spectral rigidity given by the Delta(3)(L) statistic. It is shown that some standard unfolding[...]texto impreso
Puebla, Ricardo ; Relaño Pérez, Armando ; Retamosa Granado, Joaquín | American Institute of Physics (AIP) | 2013A method to find the Excited-States Quantum Phase Transitions (ESQPT's) from parity-symmetry in the Dicke model is studied and presented. This method allows us to stablish a critical energy where ESQPT's take places, and divides the whole energy[...]texto impreso
Relaño Pérez, Armando ; Dukelsky, J. ; Pérez Fernández, P. ; Arias, J. M. | American Physical Society | 2014-10-27The ground state and spectral properties of Bose gases in double-well potentials are studied in two different scenarios: (i) an interacting atomic Bose gas, and (ii) a mixture of an atomic gas interacting with diatomic molecules. A ground state [...]texto impreso
Pérez Fernández, P. ; Cejnar, P. ; Arias, J. M. ; Dukelsky, J. ; García Ramos, J. E. ; Relaño Pérez, Armando | American Physical Society | 2011-03-03We analyze excited-state quantum phase transitions (ESQPTs) in three schematic (integrable and nonintegrable) models describing a single-mode bosonic field coupled to a collection of atoms. It is shown that the presence of the ESQPT in these mod[...]texto impreso
Khatami, Ehsan ; Rigol, Marcos ; Relaño Pérez, Armando ; García García, Antonio M. | American Physical Society | 2012-05-15We study spectral properties and the dynamics after a quench of one-dimensional spinless fermions with short-range interactions and long-range random hopping. We show that a sufficiently fast decay of the hopping term promotes localization effec[...]texto impreso
Relaño Pérez, Armando ; Gómez Gómez, José María ; Faleiro, E. ; Muñoz, L. ; Molina, R. A. ; Retamosa Granado, J. | IOP publishing ltd | 2011A survey of chaotic dynamics in atomic nuclei is presented, using on the one hand standard statistics of quantum chaos studies, and on the other a new approach based on time series analysis methods. The study of shell-model spectra in the pf she[...]texto impreso
Gómez Gómez, José María ; Faleiro, E. ; Muñoz, L. ; Molina, R. A. ; Relaño Pérez, Armando | IOP publishing ltd | 2015Shell-model calculations with realistic empirical interactions constitute an excellent tool to study statistical properties of nuclei. Using large-scale shell-model calculations in pf-shell nuclei, we study how the onset of chaos depends on diff[...]texto impreso
We study the low-lying baryon spectrum (up to 2.2 GeV) provided by experiments and different quark models using statistical tools which allow us to postulate the existence of missing levels in spectra. We confirm that the experimental spectrum i[...]texto impreso
Relaño Pérez, Armando ; Muñoz, L. ; Faleiro, E. ; Molina, R. A. ; Retamosa Granado, Joaquín | American Physical Society | 2006-03It is widely accepted that the statistical properties of energy level spectra provide an essential characterization of quantum chaos. Indeed, the spectral fluctuations of many different systems like quantum billiards, atoms, or atomic nuclei hav[...]texto impreso
Relaño Pérez, Armando ; Molina, R. A. ; Zuker, A. P. ; Retamosa Granado, Joaquín | American Physical Society | 2005-06When a matrix is reduced to Lanczos tridiagonal form, its matrix elements can be divided into an analytic smooth mean value and a fluctuating part. The next-neighbor spacing distribution P(s) and the spectral rigidity Delta _(3) are shown to be [...]texto impreso
We compare the statistical fluctuation properties of the baryon and meson experimental mass spectra with those obtained from theoretical models (quark models and lattice QCD). We find that for the experimental spectra the statistical properties [...]texto impreso
Muñoz, Laura ; Fernández Ramírez, César ; Relaño Pérez, Armando ; Retamosa Granado, Joaquín | Elsevier Science BV | 2012-03-29We present a robust analysis of the spectral fluctuations exhibited by the light meson spectrum. This analysis provides information about the degree of chaos in light mesons and may be useful to get some insight on the underlying interactions. O[...]texto impreso
Relaño Pérez, Armando ; Dukelsky, J. ; Gómez Gómez, José María ; Retamosa Granado, Joaquín | American Physical Society | 2004-08Using a 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 spacings. However, these Hamiltonians involve many-b[...]texto impreso
Relaño Pérez, Armando ; Faleiro, E. ; Gómez Gómez, José María ; Molina, R. A. ; Muñoz, L. ; Retamosa Granado, Joaquín | American Physical Society | 2004-12-10It was recently conjectured that 1/ƒ noise is a fundamental characteristic of spectral fluctuations in chaotic quantum systems. This conjecture is based on the power spectrum behavior of the excitation energy fluctuations, which is different for[...]texto impreso
Kota, V. K. B. ; Relaño Pérez, Armando ; Retamosa Granado, Joaquín ; Vyas, Manan | IOP Publishing | 2008-10-01Using the ergodicity principle for the expectation values of several types of observables, we investigate the thermalization process in isolated fermionic systems. These are described by the two-body random ensemble, which is a paradigmatic mode[...]texto impreso
Corps, Angel L. ; Molina, Rafael A. ; Relaño Pérez, Armando | American Physical Society | 2020-07-01We study the ergodic side of the many-body localization transition in its standard model, the disordered Heisenberg quantum spin chain. We show that the Thouless energy, extracted from long-range spectral statistics and the power-spectrum of the[...]